[Federal Register Volume 76, Number 143 (Tuesday, July 26, 2011)]
[Proposed Rules]
[Pages 44547-44564]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-18645]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R1-ES-2010-0023; MO 92210-0-008-B2]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition To List the Giant Palouse Earthworm (Drilolerius 
americanus) as Threatened or Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list the giant Palouse earthworm 
(Driloleirus americanus) as threatened or endangered as petitioned, and 
to designate critical habitat under the Endangered Species Act of 1973, 
as amended (Act). After review of all available scientific and 
commercial information, we find that listing the giant Palouse 
earthworm is not warranted at this time. However, we ask the public to 
submit to us any new information that becomes available concerning the 
threats to the giant Palouse earthworm or its habitat at any time.

DATES: The finding announced in this document was made on July 26, 
2011.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R1-ES-2010-0023. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, Washington Fish and Wildlife Office, 510 
Desmond Drive SE., Suite 102, Lacey, WA 98503-1263; telephone 360-753-
9440; facsimile 360-753-9008. Please submit any new information, 
materials, comments, or questions concerning this finding to the above 
street address.

FOR FURTHER INFORMATION CONTACT: Ken Berg, Manager, Washington Fish and 
Wildlife Office (see ADDRESSES). If you use a telecommunications device 
for the deaf (TDD), please call the Federal

[[Page 44548]]

Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION: 

Background

    Section 4(b)(3)(B) of the Endangered Species Act of 1973, as 
amended (Act) (16 U.S.C. 1531 et seq.), requires that, for any petition 
to revise the Federal Lists of Endangered and Threatened Wildlife and 
Plants that contains substantial scientific or commercial information 
that listing the species may be warranted, we make a finding within 12 
months of the date of receipt of the petition. In this finding, we will 
determine that the petitioned action is: (1) Not warranted, (2) 
warranted, or (3) warranted, but the immediate proposal of a regulation 
implementing the petitioned action is precluded by other pending 
proposals to determine whether species are endangered or threatened, 
and expeditious progress is being made to add or remove qualified 
species from the Federal Lists of Endangered and Threatened Wildlife 
and Plants. Section 4(b)(3)(C) of the Act requires that we treat a 
petition for which the requested action is found to be warranted but 
precluded as though resubmitted on the date of such finding, that is, 
requiring a subsequent finding to be made within 12 months. We must 
publish these 12-month findings in the Federal Register.

Previous Federal Actions

    On August 30, 2006, we received a petition dated August 18, 2006, 
from three private citizens and three other parties (the Palouse 
Prairie Foundation, the Palouse Audubon Society, and Friends of the 
Clearwater) requesting that the giant Palouse earthworm (Driloleirus 
americanus) (GPE) be listed as an endangered or threatened species 
under the Act, and critical habitat be designated. The petition 
included supporting information regarding the species' taxonomy and 
ecology, distribution, present status, and causes of decline. On 
October 9, 2007, we published a 90-day finding stating that the August 
30, 2006, petition did not provide substantial scientific or commercial 
information to indicate that listing the GPE may be warranted (72 FR 
57273). On January 24, 2008, the petitioners filed a lawsuit in the 
U.S. District Court, Eastern District of Washington against the U.S. 
Department of the Interior and the Service challenging the ``not 
substantial'' decision (Palouse Prairie Foundation et al. v. Dirk 
Kempthorne, et al., No. 2:08-cv-0032-FVS). On February 12, 2009, the 
District Court denied the Appellants' motion for summary judgment and 
granted summary judgment in favor of the Service, upholding the October 
9, 2007, determination. The U.S. Court of Appeals for the Ninth Circuit 
affirmed the District Court ruling on June 14, 2010 (D.C. no. 2:08-cv-
00032-FVS).

History of the Current Petition

    On July 1, 2009, we received a new petition dated June 30, 2009, 
from Friends of the Clearwater, Center for Biological Diversity, 
Palouse Audubon, Palouse Prairie Foundation, and Palouse Group of the 
Sierra Club (petitioners) requesting that the GPE be listed as an 
endangered or threatened species either in the entirety of its range, 
or in the Palouse bioregion as a significant portion of its range, and 
that critical habitat be designated under the Act. The petition clearly 
identified itself as such and included the requisite identification 
information for the petitioners, as required by 50 CFR 424.14(a). The 
petition included information on the GPE's taxonomy, species 
description, distribution, habitat, status, and potential threats. The 
petition was accompanied by a letter from Samuel W. James, who stated 
that he is ``the only earthworm taxonomist operating in the U.S.A.'' 
and has ``extensive experience in biodiversity of earthworms'' (2009 in 
litt.), and included additional information about the GPE and potential 
threats to the species. In an August 5, 2009, letter to the 
petitioners, we acknowledged receipt of the petition and determined 
that issuing an emergency regulation temporarily listing the species 
under section 4(b)(7) of the Act was not warranted. We also stated 
that, due to funding constraints in fiscal year 2009, we would not be 
able to further address the petition at that time but that we would 
further evaluate the petition when funding became available in fiscal 
year 2010.
    On July 20, 2010, the Service announced a 90-day finding on the 
2009 petition to list the GPE as endangered or threatened under the 
Act, and to designate critical habitat (75 FR 42059). Based on our 
review, we found the petition presented substantial scientific or 
commercial information indicating that listing the GPE as endangered or 
threatened may be warranted. We initiated a review of the status of the 
species to determine whether listing the GPE was warranted, and 
requested scientific and commercial data, and other information, 
regarding the species. This notice constitutes the 12-month finding on 
the July 1, 2009, petition to list the GPE as endangered or threatened, 
as petitioned.

Species Information

    The GPE is one of about 100 native and at least 45 nonnative 
earthworms described in the United States (Hendrix and Bohlen 2002, p. 
802). However, very little is known about the species. The GPE was 
first described by Smith in 1897, based on a collection near Pullman, 
Washington. At the time of this collection, Smith stated: ``This 
species is very abundant in that region of the country and their 
burrows are sometimes seen extending to a depth of over 15 feet'' 
(Smith 1897, pp. 202-203). His writing is based on second-hand 
information provided by R.W. Doane of Washington State Agricultural 
School (now Washington State University) in Pullman, Washington, which 
does not offer numerical or geographical context for his use of the 
terms ``very abundant'' or ``that region of the country.'' This burrow 
depth characterization has not been confirmed or contradicted by any 
subsequent field work.
    Early descriptions indicate the GPE can be as long as 3 feet (ft) 
(0.9 meters (m); Smith 1897, p. 203). Reports in the popular literature 
of GPEs up to 3.3 ft (1 m) in length (Science Daily 2006, p. 1; Science 
Daily 2008, p. 1) have not been confirmed, and collections suggest that 
specimens are more moderate in size (approximately 6 to 8 inches (in) 
(15.2 to 20.3 centimeters (cm)) in length) (Smith 1937, p. 161; Science 
Daily 2006, p. 1; Science Daily 2008, p. 1).

Taxonomy and Species Description

    The Service accepts the current taxonomic classification of the GPE 
(Subclass--Lumbricina; Superfamily--Megascolecoidea; Family--
Megascolecidae; Genus--Driloleirus; Species--americanus) (Smith 1897, 
p. 203; Fender and McKey-Fender 1990, p. 372; Fender 1995, pp. 53-54). 
While the naming conventions of the GPE have changed over time 
(Megascolides americanus in 1897 (Smith 1897, p. 203) changed to 
Driloleirus americanus by 1990 (Fender and McKey-Fender 1990, p. 372), 
there is no information provided in the petition or in our files that 
would indicate scientific disagreement about its taxonomic 
classification as a species. Adult specimens in the Driloleirus genus 
are generally distinctive, but identifying to the species level 
requires expert morphological analysis, including dissection or DNA 
evidence. Both methods take time, and there are few species experts. It 
is difficult to identify juvenile earthworm species, because they have 
no clitellum (a glandular section in the body wall, similar in shape to 
a saddle). The clitellum is a

[[Page 44549]]

key morphological difference for determining many species, and juvenile 
earthworm coloration can also vary, depending on soil type. Newly 
hatched earthworms are even more difficult to identify, and until DNA 
analysis becomes a more available tool, earthworm identification 
requires the examination of sexually mature individuals. Depending on 
site conditions and growth, an earthworm would need to be 3 to 6 months 
of age before being recognizable as being in the genus Driloleirus 
(Johnson-Maynard 2011, pers. com.).

Distribution

    Distribution of native earthworm species in the Pacific Northwest 
is limited by several factors. Pleistocene glaciation covered nearly 
the whole of Canada and the northern edge of the United States, 
eliminating earthworms from the area covered with ice (Fender 1995, p. 
54). Since the retreat of the glaciers, earthworms in the Lumbricidae 
family have been able to colonize the ice-free areas in a few 
centuries, although earthworm distribution in the Megascolecidae family 
(to which the GPE belongs) stops near the terminal moraines (ridges of 
rock, gravel and soil across valleys at the end glaciers or ice fields) 
of the ice sheet. This may be because the megascolecids prefer fine-
textured soils, which are largely absent at the edge of Pleistocene 
glaciation (Fender 1995, p. 55). Other barriers, including mountain 
ranges and arid areas (Bailey et al. 2002, p. 26), have slowed 
recolonization of the Columbia Basin.
    At the time of the original description, in 1897, this taxon was 
known only from the area around Pullman, Washington (Smith 1937, p. 
157). The GPE was originally considered to be an endemic species (a 
species native to a particular region), that uses grassland sites with 
deep soil and native vegetation of the Palouse bioregion (Wells 1983, 
p. 213; James 1995, p. 1; Niwa et al. 2001, p. 34). The Palouse 
bioregion is an area of rolling hills and deep soil in southeastern 
Washington and adjacent northwestern Idaho. More recently, this species 
has also been found in Douglas-fir forests in the Palouse region 
(Johnson-Maynard, September 21, 2010, in litt. p. 1; November 30, 2010, 
in litt. p. 1), and on the eastern slope of the North Cascades 
Mountains (Cascades) west of Ellensburg, Washington (Fender and McKey-
Fender 1990, p. 358). In 2010, the GPE was also documented in dry pine 
forest habitat near Leavenworth, Washington (Johnson-Maynard 2010, p. 
3, in litt.). This broader distribution, which is now known to include 
Latah County (Idaho), Whitman County (Washington), Kittitas County 
(Washington), and Chelan County (Washington), provides evidence that 
the species may not be endemic to Palouse grasslands.
    Confirmed GPE locations, and other potential GPE locations (DNA is 
currently being analyzed for these specimens), are identified in Table 
1. Two of the potential GPE collections are of particular interest: one 
in shrub/grassland habitat near Chelan, Washington, and one in second-
growth forest habitat east of Moscow, Idaho (Johnson-Maynard 2010, pp. 
1-2; November 30, 2010, in litt. p. 2). The DNA or morphology results 
for these specimens are not yet available to enable identification to 
the species level, but if these specimens are confirmed to be GPE, the 
currently known distribution and habitat types documented for the 
species will be expanded. One commenter provided a list of possible GPE 
locations in the Palouse region (Hall 2010, in litt. pp. 2-3), but 
acknowledged that the sites were not confirmed. Although these 
anecdotal locality reports may be helpful in identifying areas for 
future GPE surveys, they are not relevant to this finding.

                                  Table 1--Locations and Characteristics of Collections of the GPE or Driloleirus Genus
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Vegetation and other
           Site name/year                 County/State         Positive ID as GPE    site characteristics,   Collector (sources)     Survey methods, if
                                                                                           if known                comments                known
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pullman, 1897?                       Latah, ID.............  Yes..................  ......................  Collected by Doane.    .....................
                                                                                                             (Smith 1897, Gates
                                                                                                             1967).
Pullman, 1931......................  Whitman, WA...........  Yes..................  ......................  Collected by Svilha.   .....................
                                                                                                             (Smith 1937).
Pullman, 1978......................  Whitman WA?...........  Yes..................  Beneath hawthorn        Collected by Fender.   .....................
                                                                                     thicket.                (Wells et al. 1983,
                                                                                                             p. 213, credited to
                                                                                                             Fender). One mile
                                                                                                             east of Pullman.
Hwy 95/195, 1978...................  Whitman, WA...........  Yes..................  ......................  Collected by Fender.   .....................
                                                                                                             (Wells et al. 1983,
                                                                                                             p. 213; credited to
                                                                                                             Fender). Follow-up
                                                                                                             visit by Johnson-
                                                                                                             Maynard and Fender
                                                                                                             in 2006 showed
                                                                                                             habitat
                                                                                                             significantly
                                                                                                             degraded (Johnson-
                                                                                                             Maynard November 20,
                                                                                                             2010, in litt, p. 1).
Moscow Mountain, 1988..............  Latah, ID.............  Yes..................  Douglas fir forest;     Collected by Johnson   .....................
                                                                                     Under the moss and      and Johnson.
                                                                                     litter layer of a       (Palouse Prairie
                                                                                     forested site.          Foundation 2006;
                                                                                                             Johnson-Maynard,
                                                                                                             September 21, 2010,
                                                                                                             in litt. p. 1).

[[Page 44550]]

 
Ellensburg, pre-1990...............  Kittitas, WA..........  Yes **...............  ......................  Collected by Fender.   .....................
                                                                                                             (Fender 1995; James
                                                                                                             2000). ** Specimen
                                                                                                             in poor shape, but
                                                                                                             reflects properties
                                                                                                             of GPE (Fender Sept.
                                                                                                             14, 2010, in litt.
                                                                                                             p. 1; Fender, Sept.
                                                                                                             30, 2010, in litt.
                                                                                                             p. 10; Johnson-
                                                                                                             Maynard 2011, Pers.
                                                                                                             Comm.).
Smoot Hill, 2005...................  Whitman, WA...........  Yes..................  Native Palouse prairie  Collected by           Characterized
                                                                                     remnant, some shrubs;   S[aacute]nchez-de      earthworm
                                                                                     25% slope, Northwest    Le[oacute]n.           populations in two
                                                                                     aspect, 2,723 feet      (S[aacute]nchez-de     grassland types
                                                                                     elevation; Soil: silt   Le[oacute]n and        (native prairie and
                                                                                     loam, gravelly sandy.   Johnson-Maynard        CRP) in Latah
                                                                                                             2009, p.1398;          County, ID, and
                                                                                                             Johnson-Maynard        Whitman County, WA.
                                                                                                             November 30, 2010 in   Conducted surveys in
                                                                                                             litt. p. 2-3 ).        May and June of 2003
                                                                                                             Found during 2-year    through 2005.
                                                                                                             survey that included   Methods: 5 measured
                                                                                                             remnant prairie and    pits randomly
                                                                                                             Conservation Reserve   located and
                                                                                                             Program (CRP)          excavated at each
                                                                                                             grasslands in          site and earthworms
                                                                                                             Palouse.               were sampled by hand
                                                                                                                                    sorting, then
                                                                                                                                    classified to
                                                                                                                                    species.
Paradise Ridge, 2008...............  Latah, ID.............  Yes..................  Palouse prairie, some   Collected by Umiker    .....................
                                                                                     shrubs; 30% slope;      and Robertson.
                                                                                     Southwest aspect;       (Science Daily 2008,
                                                                                     3,527 feet elevation;   Johnson-Maynard
                                                                                     blue bunch              November 30, 2010,
                                                                                     wheatgrass, Idaho       in litt. p. 2-3;
                                                                                     fescue, snowberry,      Hill, 2010 in litt.
                                                                                     non-native grasses;     pp. 2-3; Johnson-
                                                                                     Soil: Loam, high        Maynard, September
                                                                                     content of gravel.      21, 2010, in litt.
                                                                                                             p. 1; Johnson-
                                                                                                             Maynard 2010 p. 2-
                                                                                                             3). Determined to be
                                                                                                             GPE based on
                                                                                                             location and partial
                                                                                                             specimen.
Paradise Ridge, 2010...............  Latah, ID.............  Yes. Identified by     Palouse prairie, same   Collected by Xu and    2010 GPE specimens
                                                              James.                 as above.               Umiker. (Johnson-      were collected with
                                                                                                             Maynard, November      electroshocker.*
                                                                                                             30, 2010, in litt.     Handsorting
                                                                                                             p. 2). Adult GPE       conducted at the
                                                                                                             found at a privately   same time did not
                                                                                                             owned prairie          result in the
                                                                                                             remnant near Moscow,   collection of GPE
                                                                                                             Idaho, 2008 and 2010   (Johnson-Maynard
                                                                                                             Paradise Ridge sites   December 21, 2010 in
                                                                                                             less than 50 feet      litt. p. 2). *Use of
                                                                                                             from each other.       electrodes and a
                                                                                                             Nearby location        generator to direct
                                                                                                             surveyed in 2005       electric current
                                                                                                             with no GPE found.     into the soil.
East of Moscow, ID, 2010...........  Latah, ID.............  Pending..............  Secondary growth        Collected by: ?        .....................
                                                                                     forest (Douglas fir).   (Johnson-Maynard,
                                                                                                             November 30, 2010,
                                                                                                             in litt. p. 2).
                                                                                                             Sample too degraded
                                                                                                             for morphological
                                                                                                             description;
                                                                                                             currently analyzing
                                                                                                             DNA.
Leavenworth, 2007..................  Chelan, WA............  Pending..............  Open forest, savanna;   Collected by           .....................
                                                                                     Relatively open         resident, initially.
                                                                                     Ponderosa pine          (Science Daily 2008,
                                                                                     forest. Compacted       Johnson-Maynard
                                                                                     area covered with       2010, pp. 3-4
                                                                                     gravel soil.            Johnson-Maynard
                                                                                                             November 30, 2010,
                                                                                                             in litt. p. 2.)
                                                                                                             Driloleirus genus;
                                                                                                             Currently analyzing
                                                                                                             DNA.

[[Page 44551]]

 
Leavenworth, 2010..................  Chelan, WA............  Yes. Adult examined    Ponderosa pine,         Collected by Xu and    Follow-up surveys
                                                              by Fender.             Arrowleaf baslamroot/   Umiker. (Johnson-      specific to
                                                                                     mule's ear, annual      Maynard 2010 p. 2-     determining
                                                                                     grasses; South          4). Multiple           Driloleirus species
                                                                                     aspect, 27% slope;      hatchling specimens--  and soil and site
                                                                                     1,846 feet elevation;   will analyze one       characteristics.
                                                                                     Soil: sandy loam.       injured hatchling      Survey conducted in
                                                                                                             for DNA.               November, 2010. Soil
                                                                                                                                    was excavated from
                                                                                                                                    one large pit
                                                                                                                                    (approximately 60 cm
                                                                                                                                    by 60 cm) at each
                                                                                                                                    site. Soil was hand-
                                                                                                                                    sorted and all
                                                                                                                                    earthworms removed
                                                                                                                                    and counted. One
                                                                                                                                    sample was collected
                                                                                                                                    from each site for
                                                                                                                                    DNA analysis.
Near Camas Meadows (near             Chelan, WA............  Pending..............  Arrowleaf balsamroot,   Collected by:          .....................
 Leavenworth), 2010.                                                                 scattered ponderosa     Fleckenstein
                                                                                     pine.                   (Johnson-Maynard
                                                                                                             December 22, 2010 in
                                                                                                             litt. p. 2) Smaller
                                                                                                             adult, will analyze
                                                                                                             DNA.
Chelan, 2010.......................  Chelan, WA............  Pending..............  Grasses, Arrowleaf      Juvenile found--will   Follow-up surveys
                                                                                     balsamroot,             analyze for DNA        specific to
                                                                                     sagebrush, sparse       (Johnson-Maynard       determining
                                                                                     ponderosa pine          2010, p. 2-4).         Driloleirus species
                                                                                     nearby; ~38% slope,                            and soil and site
                                                                                     South aspect; 2,057                            characteristics.
                                                                                     feet elevation; Soil:                          Survey conducted in
                                                                                     gravelly sandy loam.                           November, 2010. Soil
                                                                                                                                    was excavated from
                                                                                                                                    one large pit
                                                                                                                                    (approximately 60 cm
                                                                                                                                    by 60 cm) at each
                                                                                                                                    site. Soil was hand-
                                                                                                                                    sorted and all
                                                                                                                                    earthworms removed
                                                                                                                                    and counted. One
                                                                                                                                    sample was collected
                                                                                                                                    from each site for
                                                                                                                                    DNA analysis.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Table 1 identifies confirmed GPE and potential GPE locations (at 
this time just identified to Driloleirus genus; DNA analysis is 
pending), and information on survey methods for each collection where 
available. While negative survey data are important to understand the 
distribution of any species, the Service found little information on 
surveys with negative results in the Palouse, and no information on 
negative surveys outside of the Palouse. The available information on 
negative survey results is presented in Table 1.
    Earthworms are not randomly distributed in the soil (Guild 1952, as 
referenced in Edwards and Lofty 1977, p. 127), and some are difficult 
to detect. Factors that influence this non-random distribution could 
include: (1) Physical and chemical characteristics of the soil; (2) 
food availability; (3) the reproductive potential and dispersal 
capabilities of the species; or (4) interactions between these factors 
(Murchie 1958, as referenced in Edwards and Lofty 1977, p. 127). 
Earthworms also occur in patchy distributions, which make it difficult 
to determine population demographics (Whalen 2004, pp. 143, 148, 
Umicker 2009, p. 187). Edwards and Bohlen (1996, p. 90) stated that 
assessments of size, distribution, and structure of earthworm 
populations are difficult because numbers change with season, 
demography, and vertical distribution in the substrate.
    In his letter submitted with the petition, James (2009 in litt. p. 
2) states that a reasonable and sufficient effort has been made to find 
the GPE in a variety of habitats within its presumed range, and that 
these efforts have failed except in very rare instances in natural or 
little-disturbed vegetation. James also stated that the Washington 
State University team surveyed many locations (most importantly in 
agricultural lands), looking for large burrows that may indicate the 
presence of large earthworms, but only found Lumbricus terrestris (the 
common night crawler), an invasive species (James 2009, in litt. pp. 2-
3). However, recently collected and confirmed specimens that have been 
documented in forested habitats and on the eastern slope of the Cascade 
Mountains in Washington (Table 1) indicate that survey efforts for the 
GPE to date have not been adequate to establish its distribution or the 
diversity of habitat types in which it occurs. Therefore, we believe 
the petitioners' assumptions regarding the presumed distribution of the 
GPE are likely erroneous.
    Fauci and Bezdicek's study (2002, pp. 258-259) compared nonnative 
lumbricid earthworm distribution in the Palouse region of eastern 
Washington and northern Idaho. In the spring of 1999, they surveyed 46 
sites in the Palouse, including sites in agricultural fields with a 
history of conservation tillage, areas next to waterways, and perennial 
vegetation areas along road rights-of-way or on old homesteads. Survey 
methods included digging six spades of soil in a 10-square-meter area, 
then hand-sorting and examining the soil. Additional samples were taken 
if immature worms were found to ensure adults for identification. 
Although the results for the GPE were negative, the Fauci and Bezdicek 
survey was not designed to specifically find this species. In addition, 
survey protocols have not yet been developed for the GPE; therefore, it 
is uncertain the protocol used in this study would have found GPE, if 
present. If reports that the GPE lives in burrows more than 15 feet 
deep are correct, the spade sampling method used by Fauci and Bezdicek 
would appear to be inadequate to confirm the species' absence.

[[Page 44552]]

    Other negative earthworm surveys in the Palouse area were also not 
specifically designed to find the GPE. Umiker et al. (2009, pp. 184-
185, 187) compared soil characteristics, cropping practices, and 
earthworm densities in 24 agricultural fields in the Palouse, but did 
not identify the earthworms to species level in that study (p. 187). 
However, adult Driloleirus earthworms are distinctive enough that they 
likely would have been documented, had they been collected. Juvenile 
Driloleirus earthworms, on the other hand, are not distinctive 
(Johnson-Maynard 2011, pers. com.), and hence could have been missed in 
this survey. Johnson-Maynard et al. (2007, p. 338) compared earthworm 
dynamics and soil properties in conventionally tilled and no-till 
agricultural fields on one research farm in the Palouse, and found only 
the nonnative southern worm (Aporrectodea trapezoids) (p. 340). Smetak 
et al. (2007, p. 161) investigated earthworm population density in 
urban settings in Moscow, Idaho; no native earthworm species were 
collected (p. 166). Nevertheless, while the negative survey data are 
interesting, in that the GPE has not been detected in agricultural 
fields or urban areas to date, coupled with information in Table 1, 
these data demonstrate how geographically limited the known survey 
efforts have been.
    It is apparent that additional GPE surveys are needed to determine 
the range, habitat preference, and life history of this species, 
particularly in light of the recent confirmation of the species near 
Leavenworth, Washington, in forested habitat. James (2000, p. 5) 
acknowledges there have been a limited number of earthworms collected 
in the Columbia basin, which includes the eastern slope of the Cascade 
Mountains and the Palouse area, and only a small portion of potential 
habitat has been surveyed. In addition to limited survey efforts, this 
species is difficult to detect. Fender (September 14, 2010, in litt. p. 
1) noted that Driloleirus species can at times be found near the 
surface during suitable survey conditions, but if conditions are dry 
they may be undetectable. Johnson-Maynard (September 21, 2010, in litt. 
p. 2) noted that one Palouse site had negative survey results for 
native earthworms in 2005, but later sampling in 2010 detected one 
adult GPE at the same site. The Xerces Society stated that due to the 
difficulty in detecting the Oregon giant earthworm (Driloleirus 
macelfreshi) (a similar species in the same genus), abundance estimates 
have not been made, and the species' status and threats cannot be 
determined until an effective survey protocol is developed and tested 
(Xerces Society 2009, p. 3).
    Due to the difficulty in surveying for the GPE, the Idaho 
Department of Fish and Game, the Service, and others have contributed 
resources to the University of Idaho to develop appropriate survey 
protocols to address the scientific challenges associated with GPE 
surveys (Groen 2010, in litt. p. 2; Johnson-Maynard 2010, in litt. p. 
2; Science Daily 2008, p. 2). Staff at the University of Idaho, 
including Johnson-Maynard and others, are currently working to develop 
and refine sampling methods and strategies, including a soil 
electroshocking technique that appears to be promising.
    In summary, the level of survey effort for the GPE has been low, 
the species is difficult to detect, and effective survey methods are 
still being developed. There is a lack of survey data, and large 
geographic and taxonomic gaps in our knowledge (Fleckenstein 2011, in 
litt. p. 1). Researchers have only recently begun to look more broadly 
for the species including localities along the eastern slope of the 
Cascades. However, the GPE has now been documented in dry forest 
habitats, which provides further evidence that the complete range and 
distribution of the species is presently unknown, but are likely 
broader than the area identified by the petitioners.

Habitat

    Habitat requirements for the GPE are not well understood. The 
original descriptions by Smith (1897, 1937) do not present any 
descriptive information about the habitat where the specimens were 
initially collected. The GPE was originally thought to be a Palouse-
region grassland species, and several specimens have been found in 
Palouse grassland remnants (Table 1; S[aacute]nchez-de Le[oacute]n and 
Johnson-Maynard 2009, p. 1393; Science Daily 2008, p. 1; Johnson-
Maynard September 21, 2010, in litt. pp. 1-2; Johnson-Maynard, November 
30, 2010, in litt. p. 2-3; Jensen 2010, in litt. p. 6). Wells et al. 
(1983, p. 213) stated that Fender collected specimens under hawthorn 
thickets; Johnson-Maynard (September 21, 2010, in litt. p. 1) described 
the vegetation type at Johnson and Johnson's Moscow Mountain site as 
Douglas-fir forest.
    There is limited specific information on the habitat type 
associated with the GPE collected near Ellensburg, Washington. Fender 
and McKey-Fender (1990) described the location as ``in the hills west 
of Ellensburg,'' and they described the GPE range at this locality as 
extending into ``treeless areas'' (pp. 358, 366). The GPE was not 
collected in recent surveys conducted in agricultural and urban 
locations in Latah County, Idaho (Johnson-Maynard et al. 2007, p. 340, 
Smetak et al. 2007, p. 166; Umiker et al. 2009, p. 187), and Whitman 
County, Washington (Fauci and Bezdicek, 2002 p. 257). Vegetation and 
soil characteristics of confirmed and potential GPE sites are described 
above in Table 1, where that information was available. S[aacute]nchez-
de Le[oacute]n and Johnson-Maynard (2009, p. 1394; Petition, p. 5) 
observed that remaining prairie remnants in the Palouse are often steep 
or rocky, or contain shallow soil, and, therefore, may be less suitable 
for earthworms (S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, 
pp. 1394, 1398; Petition, p. 5). However, Johnson-Maynard (2010, pp. 2-
3) noted that soils at the Paradise Ridge site near Latah, Idaho, had a 
high gravel content, suggesting that the GPE may be able to exist in 
soil types that would not be expected to be preferred habitat for most 
earthworms. She further noted that past Driloleirus samples provided by 
a landowner near Leavenworth, Washington, were obtained from a 
compacted area covered with gravel. Johnson-Maynard (2010, pp. 3-4) 
described the confirmed GPE collection site near Leavenworth, 
Washington, as Ponderosa pine forest with an understory of Balsamorhiza 
sagittata (arrowleaf balsamroot) and annual grasses. Although the GPE 
has also been documented in forests on the eastern slope of the 
Cascades and in Douglas-fir forests in the Palouse, significant 
uncertainties exist as to whether the species occurs in specific types 
or ages of forests, occurs in previously logged forests, or may be 
habitat-limited because of elevation or other site characteristics.

Biology

    Earthworms are generally divided into three life-history strategies 
based on their habitat use: epigeic, endogeic, or anecic (Bouche 1977, 
as referenced in James 2000, p. 2; Edwards and Bohlen 1996, pp. 113-
115). Epigeic worms live near the ground's surface and consume organic 
litter on and near the surface. Endogeic worms (which the petitioners 
currently believe the GPE to be (James 2009, in litt. p. 3)): (1) Live 
in the upper layers of mineral soil, (2) consume organic material in 
the mineral soil or at the soil-litter interface, and (3) are often 
pale in appearance (Edwards and Bohlen 1996, p. 114). Anecic worms, 
which the petitioners initially believed the GPE to be (James 2009, in 
litt. p. 3), and we believe the GPE to be based on

[[Page 44553]]

the prevailing evidence, live in deep, semi-permanent burrows and move 
to the surface to feed on fresh plant litter. Anecic earthworms are the 
largest and longest lived of the three earthworm types (James 2000, p. 
2; 1995, p. 6), and transport fresh plant material from the soil 
surface to subterranean levels. Deep-burrowing anecic earthworms 
usually produce castings on the surface near exits to their burrows 
(Edwards and Bohlen 1996, p. 198). GPE castings were observed at the 
Leavenworth, Washington, study area (Johnson-Maynard 2010, p. 2).
    James (2009, in litt. p. 3) concluded that, based on the lack of 
pigmentation and information indicating that the species is not 
associated with surface castings, the GPE ``is probably an endogeic, 
meaning living entirely in the soil, on soil resources consisting of 
organic matter in varying stages of decomposition.'' He also states 
that deep burrow depths would be useful in avoiding dry soil conditions 
common in late summer within the range of the species (September 3, 
2010, in litt. p. 1). Fender (September 14, 2010, in litt. p. 1) thinks 
deep soils would be helpful to survival and sees no reason to doubt the 
earlier descriptions of burrowing depths.
    Characterizing earthworm life histories within one of three life-
history strategies may not be entirely instructive, because some 
species may exhibit a combination of characteristics (Bouche 1977, as 
referenced in Edwards and Bohlen 1996, p. 113). However, understanding 
an earthworm species' life history is important for evaluating 
potential threats, the pathways that expose them to threats, and how 
they might respond.
    As stated earlier, James (2009, in litt., p. 3) initially 
speculated that the GPE was an anecic species, but now believes the 
species is probably an endogeic earthworm. He indicated that this 
conclusion is based on seeing a GPE specimen and learning more about 
the genus; if the GPE lacks pigmentation in the head and does not 
defecate at the surface (i.e., leave castings), it is highly unlikely 
to have an anecic life-history strategy. We have no information 
indicating whether James has conducted field surveys for this 
particular earthworm species; however, his current opinion appears to 
be inconsistent with the existing literature, descriptions of GPE 
burrowing depths described in the literature, and field observations of 
castings by researchers at the Leavenworth, Washington, GPE location 
(Smith 1897, pp. 202-203; Fender and McKey-Fender 1990, p. 364; James 
2000, p. 5; Johnson-Maynard 2010, p. 2).
    In our 2010 90-day finding (75 FR 42059), we solicited scientific 
information on the GPE's endogeic or anecic life-history strategy to 
inform our status review. Johnson-Maynard (in litt. 2010, p. 2) stated 
that the GPE is likely anecic, based on her surveys at locations near 
Leavenworth, WA. In those studies, the GPE was associated with pores 
leading down into unconsolidated parent material, and surface castings 
were observed, which are indicative of a deep-burrowing species. 
Johnson-Maynard has conducted or been involved with a number of field 
surveys where GPE specimens were collected (see Table 1 above). 
Therefore, based on the best available scientific information, field 
observations, and the existing literature, we believe the prevailing 
evidence indicates the GPE is an anecic earthworm species, although we 
acknowledge that there are still significant uncertainties regarding 
its biological requirements.
    In summary, the current understanding regarding the life cycles of 
even quite common earthworms is inadequate and requires more study 
(Edwards and Lofty 1977, p. 68), and there are many species about which 
little is known (Edwards and Bohlen 1996, p. 46). Accordingly, there 
are significant scientific uncertainties regarding the biology, 
distribution, habitat, and population trends of the GPE. The GPE's 
distribution has been documented to include areas within the Palouse 
bioregion, and areas within the eastern slope of the Cascade Mountains 
in Washington. We do not know whether there are other occupied sites 
between or outside of these locations, as few surveys have been 
conducted, the species is difficult to survey for, and survey methods 
are still being developed.
    Documented habitat types used by the GPE in the Palouse bioregion 
include native grasslands and Douglas-fir forest. In addition, the GPE 
location near Leavenworth, Washington, is described as dry Ponderosa 
pine forest. There is very little specific information on habitat type 
at the GPE location west of Ellensburg, Washington. The Driloleirus 
earthworm species recently collected near Chelan, Washington, and east 
of Moscow, Idaho, are being identified (see Table 1 above). If these 
specimens are confirmed to be the GPE through DNA or other analysis, 
the species' range and diversity of habitat types used would be 
expanded.

Summary of Information Pertaining to the Five Factors

    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
(50 CFR part 424) set forth procedures for adding species to, removing 
species from, or reclassifying species on the Federal Lists of 
Endangered and Threatened Wildlife and Plants. Under section 4(a)(1) of 
the Act, a species may be determined to be endangered or threatened 
based on any of the following five factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    In making this finding, information pertaining to the GPE in 
relation to the five factors provided in section 4(a)(1) of the Act is 
discussed below. In addition, in making this 12-month finding on the 
petition we considered and evaluated the best available scientific and 
commercial information.
    Given the paucity of information on GPE, surrogates may be useful. 
The petitioners claim that it is appropriate to use other earthworms as 
surrogates to determine effects to the GPE, provided they are 
biologically and ecologically similar (Sappington et al. 2001, p. 2869; 
Caro et al. 2005, p. 1821; Petition, p. 10). In some instances, the use 
of surrogate species (such as other earthworms) may be helpful in 
evaluating potential effects to the GPE, provided the appropriate 
scientific controls and precautions are taken. Caro et al. (2005, p. 
1821) states ``for substitute species to be appropriate, they should 
share the same key ecological or behavioral traits that make the target 
species sensitive to environmental disturbance and the relationship 
between populations' vital rates and disturbance levels should match 
that of the target; these conditions are unlikely to pertain in most 
circumstances and the use of substitute species to predict endangered 
populations' responses to disturbance is questionable.'' The Oregon 
giant earthworm (Driloleirus macelfreshi) is in the same genus, and is 
believed to construct permanent, deep, subsurface burrows (a 
characteristic that indicates an anecic life-history strategy), and 
could potentially be an appropriate surrogate. However, the status and 
threats of this species cannot be determined until an effective survey 
protocol is developed and tested (Foltz 2009, pp. 2-3). Therefore, 
using it as a surrogate would provide little to no additional insight 
into potential threats to GPE. No other relevant surrogate

[[Page 44554]]

species have been suggested or investigated.

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Its Habitat or Range

Habitat Loss and Fragmentation
    Historical information regarding potential habitat loss is 
presented in the following discussion, for context. However, the focus 
for purposes of our analysis and response to the petition is on current 
and future habitat conditions, and whether the activities responsible 
for those conditions present a threat to the GPE such that listing 
under the Act is warranted.
    As described in the 2010 90-day finding (75 FR 42061), the 
petitioners claim that the GPE is threatened by habitat conversion, 
loss, and fragmentation from agriculture and urban sprawl in the 
Palouse region (Petition, pp. 1, 7). The petitioners cite 
S[aacute]nchez-de Le[oacute]n and Johnson-Maynard (2009, pp. 1393-1394, 
1398), who state that combined effects of land-use change, habitat 
fragmentation, and competitive interactions have caused native 
earthworm declines. James (2009, p. 1) stated that indigenous 
earthworms are sensitive to habitat disturbance, and that to find 
indigenous earthworms one must work in undisturbed or mildly disturbed 
vegetation. Undisturbed vegetation is rare in the Palouse bioregion, as 
the native grassland habitat has been reduced to less than 1 percent of 
its pre-agricultural extent (Petition, p. 8; James 2009, p. 1; Noss et 
al. 1995, p. 74).
    Estimates of native habitat conversion in the Palouse bioregion 
vary, but several studies indicate the conversion has been high: 99.9 
percent of Palouse prairie habitats have been converted to agriculture 
(Noss 1995, p. 74); 94 percent of the grasslands and 97 percent of the 
wetlands in the Palouse bioregion have been converted to crop, hay, or 
pasture (Black et al. 1998, pp. 9-10); 21 percent of previously 
forested lands have been converted to agriculture or urban uses 
(Gilmore 2004, p. 3); and less than 1 percent of the original 
bunchgrass prairie habitat remains (Donovan et al. 2009, p. 1). 
However, comments on the 90-day finding noted that habitat loss in the 
Palouse due to agriculture happened historically and is not currently 
occurring. Much of the prairie was converted to farms by 1910, and much 
of the urban growth around the Pullman area occurred on farmland, not 
remaining prairie fragments (McGregor 2010, in litt., p. 2; McGregor 
1982, p. 109). However, habitat conversion in the Palouse may still 
occur, as neither Latah County, Idaho, nor Whitman County, Washington, 
have ordinances to prevent native habitat conversion (Latah County 
Board of Commissioners 2010, pp. 1-27; Whitman County 2010, pp. 1-76).
    The petition identified several locations in the Palouse area that 
contain prairie remnants (Petition, p. 5). A study of four prairie 
remnants and adjacent Conservation Reserve Program (CRP) fields was 
carried out by S[aacute]nchez-de Le[oacute]n and Johnson-Maynard (2009, 
pp. 1393, 1395; Petition, p. 4). In that study, the researchers 
collected one GPE, and commented that many remaining prairie remnants 
are not suitable for tillage because they are often steep or rocky, or 
contain shallow soil (2009, p. 6; Petition, p. 5). They also 
hypothesized that prairie remnants may not be the preferred habitat for 
the GPE due to shallow rocky soil. They described the GPE collection 
site at Paradise Ridge near Latah, Idaho, as having a high gravel 
content (Johnson-Maynard 2010, pp. 2-3). They acknowledged that 
sampling challenges could bias survey information on the GPE, and 
cautioned that hand-sampling methods may underestimate abundance of 
anecic species (S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, 
p. 1399).
    There is no baseline (i.e., pre-agriculture) density and 
distribution information on the GPE, and there are significant 
challenges associated with surveying for this species. These 
challenges, coupled with the fact that earthworms have patchy 
distributions (Guild 1952, as referenced in Edwards and Lofty 1977, p. 
127; Murchie 1958, as referenced in Edwards and Lofty 1977, p. 127; 
Whalen 2004, pp. 143, 148; Umicker 2009, p. 187), preclude our ability 
to correlate land use impacts with GPE abundance, based on the best 
available information. The GPE has been documented in both the Palouse 
bioregion and on the eastern slope of the Cascade Mountains, near 
Ellensburg and Leavenworth, in central Washington (see Table 1 above). 
There is little descriptive information about the habitat associated 
with the GPE that was collected near Ellensburg; it isn't clear whether 
the location is grassland or a different habitat type, and the specific 
location is uncertain. James (2009 in litt., p. 2) speculated the 
Ellensburg site collection is a relict of a distribution that must have 
been more or less continuous at one time, but due to climate change and 
increased aridity has now become fragmented. Fender and McKey-Fender 
(1990) described the locality as being ``in the hills west of 
Ellensburg,'' and noted that the range of the GPE extends into 
``treeless areas'' (pp. 358, 366). A report by Adolfson Associates 
(2005, p. 1) was presented as evidence of urban sprawl being a threat 
to GPE habitat. However, this report was limited to areas within the 
City of Ellensburg, Washington boundary, and is not particularly 
instructive in terms of correlating future urban development with loss 
of GPE habitat because pre-development density or distribution or both 
in that area are unknown. The petitioners also claim the grasslands 
around Ellensburg have been extensively modified by agriculture, 
similar to the Palouse bioregion (Adolfson Associates 2005, p. 2; 
Petition, p. 8; James 2009, in litt., p. 2). However, the best 
available information is insufficient to determine or infer how or 
whether the GPE has been impacted by habitat loss and fragmentation in 
this area, because we have no baseline information with which to 
correlate land use modification with GPE abundance.
    The best available scientific information is also inconclusive as 
to whether the GPE occurs in a certain forest type or age, or whether 
the species occurs in a broad variety of habitats. The GPE site near 
Moscow, Idaho, is in Douglas-fir forest habitat, and the Leavenworth, 
Washington, site is in dry ponderosa pine forest. Quigley et al. (1996, 
p. 54) stated that in the Columbia Basin, the total area in forest has 
remained relatively constant during the last two centuries, and broad 
indicators of sustainability indicate that Basin forest acreage and 
inventory volumes are relatively constant. If the GPE is a forested 
habitat generalist, it could be stable in forested locations; however, 
if it requires a forest of a specific type or age it may or may not be 
impacted by habitat loss, depending on the type of development activity 
involved. In either case, the available scientific evidence does not 
address that uncertainty.
    In summary, the GPE's current and historical population size, 
distribution, and range of habitat types used are unknown. Based on 
recent collections, the GPE's range outside of the Palouse region has 
been expanded and now includes portions of the eastern slope of the 
Cascade Mountains. The GPE has also been documented in both grassland 
and forested habitats in the Palouse. However, survey efforts have been 
limited, and sampling protocols are still being developed to improve 
researchers' ability to detect the species during field investigations. 
While habitat conversion may occur and there may be local impacts, the 
GPE range is much wider than previously known and includes more diverse 
habitats than previously

[[Page 44555]]

known. Because we cannot identify the full extent of the GPE's range or 
the varieties of habitat types it may use, we are unable to correlate 
habitat conversion with GPE abundance. Therefore, for the reasons 
stated above, the best available scientific information does not 
indicate current or future habitat loss or fragmentation represents a 
threat to the species.
General Impacts to Soil Characteristics
    The petitioners present several claims in their petition, each of 
which has been evaluated and addressed below. They claim that 
earthworms or their grassland habitats are influenced by soil 
disturbance, tillage, traffic, food sources, chemical and pesticide 
residues, and soil microclimate (Jennings et al. 1990, p. 75; Edwards 
and Bohlen 1996, pp. 283-289; Edwards et al. 1995, pp. 200-201; USDA-
NRCS 2001, p. 2; Petition, p. 10). Moisture, temperature, and food 
availability influence earthworm populations in general, and earthworms 
need the organic matter found in the topsoil that agriculture removes 
(James 2000, pp. 1-2; Petition, p. 11). Bare soil can increase the 
effects of flooding, drought, or other weather conditions due to the 
lack of vegetation that buffers soil from extreme moisture, dryness, 
and temperature fluctuations. These conditions can temporarily or 
permanently make soils unusable by earthworms (James 2000, pp. 1-2; 
Petition, p. 11). James (2009, in litt., p. 1) stated that earthworms 
are highly sensitive to habitat disturbance, such as forest clear 
cutting or conversion of any habitat to agriculture, and the native 
earthworms are generally destroyed by any type of drastic and sudden 
habitat modification. One commenter stated there may have been long 
periods of bare soil historically in the Palouse region, but seeding 
and fertilizing technology improvements now enable farmers to prepare 
seedbeds with minimal disturbance (McGregor 2010, in litt., p. 2). 
James also stated, ``when seeking the indigenous earthworms, it is 
almost always a complete waste of time to work in anything but 
undisturbed or mildly disturbed stands of vegetation'' (James 2009, in 
litt., p. 1). GPE have been found in forested locations, but it is 
unknown whether these are previously disturbed habitats.
    We acknowledge that soil disturbance has occurred and may still be 
occurring in GPE habitat. However, we currently have no information 
linking soil disturbance with GPE presence or absence. Survey efforts 
for GPE have been limited, and sampling protocols remain to be 
developed. Until we have a better understanding of the species' 
distribution and habitat information, we are unable to determine with 
reasonable confidence whether the GPE uses disturbed or undisturbed 
habitats, or both. Therefore, the best available scientific information 
does not indicate soil disturbance is a threat to the GPE.
Soil Compaction
    The petitioners claim that soil compaction from farm machinery or 
other activities can affect earthworms by making burrowing and feeding 
more difficult (James 2000, p. 9), by decreasing soil pore size and 
thereby decreasing nutrient retention and changing the soil food web 
(Niwa et al. 2001, pp. 7, 13), or by favoring nonnative earthworms that 
prefer course soils rather than the fine soils apparently preferred by 
the GPE (Fender and McKey-Fender 1990, p. 364; Petition, p. 11). 
Johnson-Maynard (September 21, 2010, in litt., pp. 2-3) noted that the 
effects of soil compaction on earthworm density can vary based on the 
species' ecological strategy (i.e., anecic versus endogeic); larger 
species, such as anecic earthworms, have been found to be less 
sensitive to soil compaction than smaller species (Cluzeau et al. 1992, 
p. 1661) and may be more abundant in compacted areas compared to non-
compacted areas (Cuendet 1992, p. 1467). Fender (1995, p. 57) has often 
found other Argilophilini worms (a tribe of native Pacific Northwest 
earthworms that includes the GPE) in compacted trails; Capowiez et al. 
(2009, p. 214) notes that our current knowledge of the sensitivity of 
earthworms to compaction is limited. In addition, the assumption that 
compaction would favor exotic species over native species due to their 
preference for finer-textures soils is invalid; while compaction does 
impact total porosity and pore size distribution, it does not alter 
soil texture (Johnson-Maynard, September 21, 2010, in litt., p. 3). 
Johnson-Maynard states that generalizations such as those presented by 
the authors of the 2009 petition, suggesting that compaction favors 
nonnative species, should be interpreted with caution (Johnson-Maynard, 
September 21, 2010, in litt., p. 3). In addition, survey efforts for 
the GPE have been limited, and sampling protocols remain to be 
developed. Until we have a better understanding of the species' 
distribution and habitat information, we are unable to determine with 
reasonable confidence whether soil compaction is occurring in GPE 
habitat, and if it is, whether it is resulting in a negative response 
in the species. Therefore, the best available scientific information 
does not indicate soil compaction is a threat to the species.
Soil Chemistry
    The pH scale describes how acidic or basic a substance is, and 
ranges from 0 to 14, with 7 being neutral, below 7 being acidic, and 
greater than 7 being basic. The petitioners cite soil chemistry 
effects, notably a reduction in soil pH from nitrogenous fertilizer 
application, as having deleterious effects on earthworms (Ma et al. 
1990, p. 76), and state that generally earthworms do not thrive in 
soils with a pH below 5 (Petition, p. 11; Edwards and Lofty 1977, p. 
234). However, the best available scientific information related to the 
responses of earthworms to pH appears to both support and contradict 
the petitioners' claim with regard to the GPE. Soil pH is a factor that 
often greatly affects earthworm populations, both in numbers of 
individuals and numbers of species. According to the Natural Resources 
Conservation Service (USDA-NRCS 2001, p. 5), earthworms do not thrive 
in soils with a pH below 5 (USDA-NRCS 2001, p. 2; Edwards and Lofty 
1977, p. 234; Edwards and Bohlen 1996, p. 276). However, one Australian 
study of tillage effects to one native anecic earthworm species 
(Spencefiella hamiltoni) described the surface soil in the study area 
as highly acidic (pH = 4.1), with the pH increasing (or acidity 
decreasing) with depth (pH = 5.0 at 0.8 meters) (Chan 2004, p. 90). 
Some earthworm species are intolerant of acid soil conditions, some are 
tolerant, and others can tolerate wide ranges of soil pH (Edwards and 
Bohlen 1996, p. 142). Because soil pH is related to other soil factors, 
such as clay content, or cation exchange capacity (the ability to hold 
plant nutrients), it is often difficult to establish a direct cause-
and-effect relationship between soil pH and the size of earthworm 
populations (Edwards and Bohlen 1996, p. 144).
    Fender (1995, p. 56) stated that Argilophilini worms appear to have 
higher tolerance than lumbricids (nonnative earthworms, such as the 
night crawler) for low pH (below 5, acidic) soils; high clay; and 
resinous, low-nitrogen, plant litter. S[aacute]nchez-de Le[oacute]n and 
Johnson-Maynard (2009, pp. 1397, 1399) found a significant negative 
interaction between soil pH and mean earthworm density and mean 
earthworm fresh weight. The nonnative southern earthworm (Aporectodea 
trapezoids) was more abundant in CRP sites with lower pH values (pH 5.9 
to 6.2) than prairie soils (pH 6.3 to 6.6) in a study of four paired 
CRP and prairie remnant sites. Their data did not support their 
hypothesis that native

[[Page 44556]]

earthworms would be dominant in prairie remnants and exotic earthworms 
dominant in CRP set-aside lands (S[aacute]nchez-de Le[oacute]n and 
Johnson-Maynard 2009, pp. 1398). In that study, one GPE was collected 
during sampling at the Smoot Hill prairie remnant study site. In the 
study, the prairie remnants' mean soil pH at depth was pH 6.3 (20-30 
cm), pH 6.5 (10-20 cm), and pH 6.6 (0-10 cm), while in the CRP study 
sites the mean soil pH at depth was pH 6.2 (20-30 cm), pH 6.0 (10-20 
cm), and pH 5.9 (0-10 cm) (S[aacute]nchez-de Le[oacute]n and Johnson-
Maynard 2009, p. 1397). The researchers stated they were unsure whether 
lower pH (more acid) in CRP sites correlated with some other non-
measured soil parameter, such as previous fertilizer applications and 
resultant increased organic matter. They hypothesized the negative 
relationship between earthworm density and soil pH could be a 
reflection of a past land use rather than a direct effect of soil pH on 
earthworms (S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, p. 
1399). Other studies in the Palouse region demonstrated the mean soil 
pH in direct-seeded agricultural fields was pH 5.35, and in 
conventional tillage fields pH 5.61 (Umiker et al. 2009, p. 184). One 
commenter (McGregor 2010, in litt., p. 4) stated less than 0.5 to 1 
percent of the soils sampled in the Palouse have pH levels below 5.
    In summary, studies investigating relationships between earthworms 
and soil pH indicate that earthworm response can vary with species, 
location, life-history strategy, or other attributes. The best 
available scientific information on this relationship for the GPE is 
limited (e.g., to our knowledge, only the Smoot Hill study has 
investigated the potential soil pH relationship). There is significant 
uncertainty regarding the correlation between soil pH and GPE 
occurrence or persistence, and insufficient data to identify pH cause-
and-effect relationships that might be limiting for the persistence of 
this species. However, in the Palouse region, soil pH levels do not 
appear to be so acidic (below pH 5) that they negatively affect 
earthworms generally. Also, the GPE may be more tolerant to acidity 
than some species of earthworms. In addition, the range of the GPE is 
wider than previously known, and includes pine forests on the eastern 
slope of the Cascades, although the full extent and type of forested 
habitats occupied by the GPE are not yet known. Detailed soil 
characteristics are not known for the GPE location near Leavenworth, 
Washington. Accordingly, the best available information does not 
indicate that changes in soil chemistry represent a threat to the GPE.
Tillage and Agriculture
    The petition states that tillage removes the original topsoil, 
which may reduce earthworm burrow densities, soil aeration, soil 
infiltration rates, and the amount of organic matter available to the 
GPE for forage (Petition, pp. 10-11). Literature cited by the 
petitioners stated the original topsoil has been lost from 10 percent 
of Palouse cropland, and 60 percent of cropland has lost 25 to 75 
percent of its topsoil (Veseth 1986b, p. 2). The petition did not 
present detailed information on agriculture activities in the 
Ellensburg area, although the Adolphson Associates report (2005, pp. 
14-22) presented with the petition includes maps and photographs 
depicting areas converted to agriculture within the Ellensburg, 
Washington, city boundaries.
    The potential threats to the GPE from tillage and cultivation are 
reduced food sources and burrow compaction, but would likely vary 
depending on its life-history strategy. Annual crops put a small 
fraction of their production into root mass (James 2009, in litt., pp. 
3-4), whereas perennial prairie grasses put approximately 50 percent of 
their annual production into roots, which provide resources for soil 
invertebrates (including endogeic earthworms). Endogeic earthworms, 
which the petitioners assert the GPE to be (James 2009, in litt., pp. 
3-4), would probably be more susceptible to agricultural activities 
that reduce soil organic matter, based on their need for organic matter 
as a food source. However, anecic earthworms use surface litter as a 
food source, and the best available scientific information supports the 
GPE being an anecic earthworm species. In either case, surveys to date 
in the Palouse have not documented the GPE in either agricultural 
fields or CRP lands (Fauci and Bezdicek, 2002, p. 254; S[aacute]nchez-
de Le[oacute]n and Johnson-Maynard 2009, p. 1393; Johnson-Maynard et 
al. 2007, p. 340). Therefore, we have no information indicating that 
the GPE would be exposed to reduced soil organic matter or reduced 
surface litter caused by ongoing cultivation in the Palouse region.
    One Australian study demonstrated that 3 years of tillage reduced 
earthworm burrow density by nearly 90 percent (Chan 2004, p. 89; 
Petition, p. 10), which reduced the maximum infiltration rate of the 
soil and significantly increased the likelihood of runoff and erosion. 
Chan's study (2004, p. 90) compared tillage effects to soil 
infiltration by monitoring burrow density for the North Auckland worm 
(Spenceriella hamiltoni), an anecic member of the Megascolecidae (in 
the same family as the GPE), under three conditions: no-till (crops 
drilled directly into ground with a special slit drill), conventional 
one-pass, and conventional two-pass tilled agriculture (Chan 2004, p. 
94). The effect of tillage on earthworm abundance is usually negative 
because tilling causes physical damage and burial of residues, although 
tillage could also increase the abundance of some earthworm species due 
to increases in food supply by incorporation of residues into the soil 
(Chan 2004, p. 90). In this study, tillage was found to decrease burrow 
density and water infiltration into the soil (Chan 2004, pp. 89, 94). 
The author concluded that under cropping, preservation of earthworm 
burrows can be achieved by adopting conservation tillage techniques 
(Chan 2004, p. 96). Conservation tillage techniques generally involve 
establishing crops in a previous crop's residues, which conserves water 
and minimizes soil disturbance and erosion.
    Johnson-Maynard (September 21, 2010, in litt., p. 2) discusses 
studies in which tillage effects on earthworm density were found to be 
dependent on the ecological grouping of earthworms in an area (i.e., 
anecic or endogeic). Chan (2001, pp. 179, 185-187) found in a 3-year 
study that tillage had a strong negative impact on anecic species due 
to a combination of direct damage, burial of residue (food source), and 
destruction of earthworm burrows, while endogeic species were 
positively affected in the short term due to their smaller size (less 
physical damage) and increased availability of organic matter. In the 
Palouse bioregion, tillage removes the original topsoil, which may 
reduce earthworm burrow densities, soil aeration, soil infiltration 
rates, and the amount of organic matter available to the giant Palouse 
earthworm for forage (Veseth 1986b, p. 2; Petition, pp. 10-11). Edwards 
and Bohlen (1996, p. 215) stated that earthworm populations were much 
larger in soil that was manipulated using no-till methods. No-till 
agriculture accounted for 14,563 acres (5,893 hectares), or roughly 5 
percent of the total surveyed acreage in the Palouse in 1989, up from 
the previous 5-year average (1984-1988) of 3 percent (Hall 1999, p. 
15).
    The GPE has been documented in the Palouse in remnant native 
grassland and in Douglas-fir forests, and in ponderosa pine forest at 
the Leavenworth site near Chelan, Washington. The GPE distribution is 
wider than previously known, but its total distribution remains 
uncertain because the species is very

[[Page 44557]]

difficult to detect, survey protocols are still being developed, and 
the level of survey efforts within and outside of the Palouse area has 
been very low. While there may have been historical impacts to the GPE 
from agriculture in the Palouse, the magnitude of threats from those 
activities is difficult to determine because we have no baseline 
population or distribution information with which to make a comparison, 
other than the anecdotal statement in Smith (1897, pp. 202-203). In 
addition, to date the GPE has not been found in agriculture fields in 
the Palouse, and we have no information that indicates the GPE is or 
will be exposed to tillage and agriculture. Accordingly, the best 
available information does not indicate that tilling and agriculture 
represent a threat to the GPE.
Grazing
    James stated that grazing degrades earthworm habitats, potentially 
to the point of causing extirpation, and that soil compaction from 
livestock grazing can affect earthworms by making burrowing and feeding 
more difficult (James 2000, pp. 9-10). The petition also claims that 
livestock grazing changes the quality and accessibility of detrital 
material, decreasing organic matter available to earthworms through 
conversion of herbage to partly digested clumps of organic matter 
(James 2000, p. 9; Petition, p. 14).
    The petitioners describe livestock grazing as a pervasive land use 
in the range of the GPE. James (2000, p. 9) stated: (1) Livestock 
grazing can cause soil compaction, thereby making burrowing and feeding 
more difficult for earthworms; (2) effects are variable by earthworm 
species or habitat type (or both); (3) large earthworm species are less 
heavily impacted by grazing; and (4) ``without further knowledge about 
native earthworms and the presence or absence of earthworms in lands 
subject to grazing in the Columbia River basin assessment area, it is 
of little use to speculate further.'' Cluzeau et al. (1992, pp. 1661, 
1663) demonstrated intensive trampling by cattle can reduce earthworm 
densities, particularly for smaller species and those living near the 
surface. No specific information was provided by the petitioners 
regarding the extent of livestock grazing impacts in the Palouse or 
Ellensburg areas. However, several individuals (Field 2010, in litt., 
p. 2; Jensen 2010, in litt., p. 6) commented that grazing can benefit 
some earthworms through increasing organic matter and plant species 
diversity (Dorsey et al. 1998, p. 2; Taylor and Neary 2008, p. 2). We 
cannot assess the distribution of the GPE in relation to grazing 
activities or grazing intensity because the species' range is unknown, 
but is wider than previously documented, there have been very few 
surveys, and the habitats used by the species are more variable than 
previously known. However, the best available information indicates 
grazing can sometimes benefit earthworms and larger species like the 
GPE may be less impacted by grazing than smaller species. Accordingly, 
based on the best available information, grazing has not been 
demonstrated to be a threat to the species.
Chemical Applications
    Earthworms have been shown to be sensitive to some pesticides 
(Edwards and Bohlen 1996, pp. 283-285), and the toxicity varies 
depending on the type of pesticide used. Generally, carbamates (organic 
compounds derived from carbamic acid and frequently used in 
insecticides) are the most toxic (Edwards and Bohlen 1996, pp. 283-
285). In addition, although chemicals may not result in direct 
toxicity, they may have indirect effects such as reduction in organic 
matter, which is a food source for earthworms. Contaminant exposure and 
toxicity depends on a wide range of chemical, physical, and biological 
factors, and the rate of application. Specific knowledge of the fate 
and transport of the chemical within the environment, physicochemical 
attributes of the exposure media, and biological characteristics of the 
organism are required to determine if a species may be impacted by 
environmental contaminants. Although pesticide application is 
widespread within the Palouse, information on GPE distribution, 
biology, and life history is limited. There is significant uncertainty 
with regard to determining the potential impact pesticides might 
present to this species, and what application rate(s) would be required 
for those impacts to rise to a level of being a threat to the species. 
Exposure could also vary, depending on the GPE's life-history strategy. 
Anecic species (which we believe the GPE to be based on the best 
available scientific information) may have less exposure than other 
forms. For example, the black-headed worm (Aporrectodea longa), an 
anecic species, was determined to be less susceptible to pesticides 
because of its ability to burrow deep into the soil. This species also 
undergoes an obligatory diapause in the summer months, which may limit 
pesticide exposure (Wheatley and Hardman 1968, as referenced in Edwards 
and Bohlen 1996, p. 280; Gerard 1967, as referenced in Edwards and 
Bohlen 1996, p. 280). It is unknown whether the GPE undergoes a 
diapause. In addition, in a midwestern United States study on 
agriculture and earthworms, Simonson et al. (2010, p. 147) found the 
most commonly applied pesticides and increased crop diversity did not 
have a significant effect on either the endogeic or anecic earthworm 
groups.
    From 1992 through 1995, pesticides were assessed as part of the 
National Water-Quality Assessment (NAWQA) Program, and at least one 
pesticide was detected within 97 percent of surface water samples 
collected within the Palouse bioregion. No pesticides were found in 
groundwater (the only source of drinking water in the area) at 
concentrations that exceeded drinking water standards or guidelines 
(Roberts and Wagner 1996, p. 15). Although some data are available for 
pesticide presence in surface and groundwater, there is little 
information on pesticide presence or concentrations in soils within 
documented GPE habitat. Many currently used pesticides are water 
soluble and are much less persistent in soils than the organochlorine 
pesticides used in the past.
    Approximately 700,000 pounds of commonly used pesticides are 
applied in the Palouse bioregion annually (Roberts and Wagner 1996, p. 
2), and agricultural interests in the Palouse region apply many 
herbicides to control invasive and noxious plants (Hall et al. 1999, p. 
12, Table 3.08; Kellogg et al. 2000, p. 2). Wagner et al. (1995, pp. 
21-22) identified several pesticides used in an area within the Palouse 
bioregion, several of which were detected in water samples, including 
Triazine (Atrazine) (pp. 15-16, Table 4), although several comments 
(e.g., McGregor in litt., p. 4) stated that Triazine family herbicides 
are not used commercially for agriculture in the Palouse. The petition 
claims no-till farming uses herbicides rather than tilling for weed 
control, resulting in higher herbicide use in no-till fields than in 
tilled fields (Veseth 1986a, p. 1; Petition, p. 12); however, no-till 
farming was estimated in 1989 to be used on only 5 percent of the 
fields in the Palouse region (Hall 1999, p. 15). Several individuals 
from the Palouse bioregion commented that no-till farming uses 
glyphosate herbicides (Jensen 2010, in litt., p. 5; McGregor 2010, in 
litt., p. 2; Mick 2010, in litt., p. 2), which studies show have no 
toxicity for earthworms when properly applied (Edwards and Bohlen 1996, 
p. 304). Individuals also commented that agricultural users apply 
fertilizers and pesticides sparingly and with precision because of the 
costs involved (Barstow

[[Page 44558]]

2010 in litt., p. 2; Jensen 2010 in litt., p. 5).
    There is limited information available on pesticide use outside of 
the Palouse bioregion in the vicinity of documented GPE locations. One 
study detected such chemicals in irrigation canal monitoring sites in 
the Yakima watershed (Johnson 2007, p. 1). However, the monitoring 
sites used for the Johnson (2007) study appear to be lower in the 
watershed than the Ellensburg GPE location (Fender and McKey-Fender 
1990, pp. 358, 366). Although groundwater and surface water pesticide 
monitoring studies provide an indication of pesticide use in the 
general area, the data are not informative on whether pesticides are 
present in GPE-documented habitats. We are also unaware of any 
pesticide monitoring studies in the vicinity of the GPE location near 
Leavenworth, Washington.
    In summary, agricultural lands have been the primary focus areas 
for pesticide and herbicide monitoring studies; however, the GPE has 
not been documented to date in these types of areas. Although we have 
some information on pesticide applications in the Palouse area, and 
some generalized information regarding pesticide toxicity to 
earthworms, the available information is inadequate to determine how 
and whether those pesticides impact soils or habitats occupied by the 
GPE. We have some limited pesticide application information for the 
Ellensburg, Washington, vicinity, although the data are not 
particularly enlightening with regard to proximity to the GPE location, 
and we have no pesticide information related to the GPE location 
documented near Leavenworth, Washington. However, information on 
another anecic species (Wheatley and Hardman 1968, as referenced in 
Edwards and Bohlen 1996, p. 280; Gerard 1967, as referenced in Edwards 
and Bohlen 1996, p. 280) indicates deep-burrowing anecic species are 
less susceptible to pesticides. In addition, the prevailing information 
indicates the GPE is an anecic species, and anecic species have less 
exposure to pesticides than other earthworm life-history forms. We do 
not have information on GPE pesticide exposure in areas outside of the 
Palouse region, and the exposure will vary with the distribution, 
habitat types, and pesticide uses in those areas. The GPE has a wider 
range and occurs in more diverse habitats than previously known, and we 
have little information on pesticide applications occurring in those 
areas. Accordingly, the best available scientific information does not 
indicate the application of pesticides or herbicides is a threat to the 
GPE.
Urbanization and Rural Development
    The petitioners claim that urban sprawl and rural development 
negatively impact GPE habitat in the Palouse and Ellensburg areas. The 
Ellensburg, Washington; Pullman, Washington; and Moscow, Idaho human 
populations increased by approximately 76, 88, and 73 percent, 
respectively since 1980 (Petition, p. 12; http://www.census.gov, figure 
4). The petition states that urban development compacts soil, removes 
topsoil, and favors nonnative, invasive earthworms (Petition, pp. 12-
13), and road construction affects remaining prairie remnants 
(Petition, p. 13). If urban or rural development were to occur on 
remnant prairie habitats in the Palouse, there may potentially be an 
impact to the GPE. However, the Palouse prairie is not the only habitat 
type used by the GPE, as the species has also been located in Douglas-
fir forest in the Palouse and in ponderosa pine forest near 
Leavenworth, Washington (see Table 1 above).
    The petitioners (Petition p. 13) expressed concern about a 
potential rerouting of U.S. 95 through a large prairie remnant in the 
Palouse bioregion south of Moscow, Idaho. The planning for this project 
is ongoing (Idaho Department of Transportation (IDOT) 2011a, p. 1). 
There were three action alternatives under consideration (IDOT 2011c, 
p. 1), one of which (the eastern alternative) would impact Paradise 
Ridge, an area where the GPE has been documented. However, the IDOT 
forwarded only alternatives that would have no direct impact on rare 
plant communities (including remnant prairie habitat) for further 
analysis (IDOT 2011b, p. 21, 25), and as a result, the Paradise Ridge 
GPE site will not be affected by the IDOT project. Urban and rural 
development in prairie remnants is still possible, given that Latah 
County, Idaho, and Whitman County, Washington, do not prohibit this 
type of development (Latah County Board of Commissioners 2010; Whitman 
County 2010); however, there are significant scientific uncertainties 
regarding the full extent of habitat types used by the GPE, as well as 
the species' distribution, range, and population trends. In summary, 
the best available scientific information does not indicate that 
urbanization and rural development are threats to the GPE.
Forest Management
    The impact of forest management actions on soils varies, and 
uneven-aged management (i.e., selective harvest) can result in 
machinery-induced soil compaction over a larger area than even-aged 
management (i.e., clearcut harvest) (Harvey et al. 1994, p. 44). 
However, while selective timber harvest practices may result in soil 
disturbance or compaction from heavy equipment, there will be less loss 
of surface or soil organic matter than when clearcut timber harvest 
methods are used (James 2000, p. 10). Forest management operations can 
alter the cycling of above-ground organic materials and their 
incorporation into soil (Harvey et al. 1994, p. 11), which may result 
in not only impacts to soil nutrients, but also changes to soil 
characteristics such as water-holding capacity, aeration, drainage, and 
cation exchange.
    The GPE has been documented in Douglas-fir forest at Moscow 
Mountain in the Palouse, and recently confirmed in dry ponderosa pine 
forest near Leavenworth, Washington (see Table 1 above), although 
information regarding details on the forest stand at the GPE locations, 
and the extent of habitats the GPE occupies in forested environments, 
is incomplete. Forest types have changed in the Columbia Basin since 
historical times, although the numbers of forested acres are not 
substantially different (Quigley et al. 1996, p. 54). The potential 
impacts to the GPE from forest management activities would likely 
depend on whether the species requires certain forest types or ages, 
and if so, the specific nature of the management prescription being 
applied in those areas. There are uncertainties with regard to whether 
the GPE is restricted to certain types of forests, certain ages of 
forest, or certain elevations or other site characteristics, or whether 
surface vegetation is relevant to the species. If the GPE occurs in 
multiple types and ages of forest, the availability of a particular 
forested habitat type may not be a limiting factor, and forest 
management may have little impact.
    James stated in 1995, that he can ``confidently state that nothing 
is known of the impact of any management practice on any Columbia River 
Basin native earthworm species'' (James 1995, p. 12). However, in 2000, 
James stated that logging: (1) Degrades earthworm habitat, potentially 
to the point of causing extirpation and changes in plant communities, 
and (2) may degrade habitat through changing soil type, soil 
temperature, moisture regime, or food resources (James 2000, p. 10). In 
his 2000 study, James also related the primary effect of tree removal 
on endogeic earthworms to soil climate and the availability of surface 
and soil organic matter sufficient to support earthworms until second-
growth plants become established. James also stated

[[Page 44559]]

that epigeic species would be expected to suffer most from the loss of 
tree cover because the preferred microhabitat would be less hospitable 
and ultimately less abundant, with the loss of annual leaf input, and 
indicated that disturbance caused from heavy equipment use may be the 
most deleterious to earthworms (Shaefer and others 1990, in James 2000, 
p. 10). However, James did not discuss how these types of activities 
would affect an earthworm species with a deep-burrowing, anecic, life-
history strategy (James 2000, p. 10), such as the GPE. The Service 
recognizes that forest management activities can affect soils, 
temperatures, and vegetation, and the impacts would vary with types of 
forest management, types of forest, and habitat needs of the GPE. 
However, we were unable to determine how much forested habitat the GPE 
occupies or where it occurs in forested habitat (other than the above 
confirmed localities). Additional surveys will be needed to determine 
the extent of forested habitat occupied by the species. In addition, we 
have no information to indicate how GPE would respond to different 
types of forest management activities. Therefore, the best available 
information does not indicate that forest management activities 
represent a threat to the GPE.
Summary of Factor A
    The GPE is known to occur in both grassland habitats and forested 
habitats in the Palouse. Native grassland habitats in the Palouse have 
declined to very low levels; information on changes to forested 
habitats in the Palouse is less well understood. The species' range 
outside of the Palouse region is substantially greater than was 
previously known, and includes portions of the eastern slope of the 
Cascade Mountains. Survey efforts have been limited, it is difficult to 
survey for the species, and effective survey methods remain to be 
developed. In addition, there are significant scientific uncertainties 
regarding the GPE's distribution, habitat diversity, biology, and 
population trends, which need to be resolved to be able to conduct a 
credible scientific assessment of potential threats to the species. The 
best available information is inconclusive with regard to whether soil 
pH is a limiting factor, or whether there are certain types of 
management activities that affect soil pH in a manner that presents a 
threat to the GPE. The literature suggests that compacting soils may 
result in impacts to earthworms, depending on their life-history 
strategy. However, there is no information with which to determine with 
reasonable confidence whether soil compaction is occurring in GPE 
habitat, and if so, whether it would result in a negative response in 
the species.
    While there may have been historical impacts to the GPE from 
agricultural conversion in the Palouse, most agriculture conversion 
activities were completed by 1910 (McGregor, 1982, p. 109). The extent 
to which agricultural activities currently present a threat to the GPE 
is undeterminable, given the limited information available on the 
species' life history, its range, and the diversity of habitat types 
where it occurs. However, the species has not been collected in 
agricultural areas to date. The extent of the GPE's range and habitat 
types used beyond the Palouse is also unknown. While there may 
potentially be impacts from grazing activities, we have an incomplete 
understanding of the species' occupied habitat, whether grazing occurs 
therein, the magnitude and intensity of grazing activities in those 
areas, and the GPE's exposure to grazing impacts. We have some 
information on pesticides used in the Palouse area, and we have 
generalized information on pesticide toxicity to earthworms. However, 
we are unable to correlate that information to soils or habitats used 
by the GPE in the Palouse or elsewhere, and whether the GPE is exposed 
to those chemicals. The limited information on pesticide applications 
in the Ellensburg, Washington, vicinity is not instructive with regard 
to whether or not those activities might threaten the GPE, and there is 
no information related to pesticide application in the Leavenworth, 
Washington, GPE locality. Because of our limited knowledge of the 
species' range and occupied habitat, we cannot credibly evaluate the 
threat of urban or rural development to the species. We recognize that 
forest management activities can affect soils, temperatures, and 
vegetation, but there is no information correlating these activities to 
a possible negative response by the GPE. In summary, there is very 
little information available, and the best available scientific 
information does not indicate the present or threatened destruction, 
modification, or curtailment of the GPE's habitat or range from any of 
the above activities constitutes a threat to the species such that 
listing under the Act is warranted.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The petition did not identify overutilization for commercial, 
recreational, scientific, or educational purposes as a potential threat 
to the GPE. Unlike butterflies, for example, earthworms are not likely 
targets for collection by hobbyists. Recent records of the GPE are 
based on the few individuals that were killed during or after their 
collection (fewer than 10). While we anticipate some additional GPE 
mortality due to scientific collection as we learn more about the 
species, we have no reason to believe the loss of a few individuals for 
scientific purposes would present a threat to the continued existence 
of the species. Therefore, we conclude that overutilization for 
commercial, recreational, scientific, or educational purposes is not a 
threat to the species such that listing under the Act is warranted.

Factor C. Disease or Predation

    The petition did not identify any threats to the GPE related to 
disease or predation. Hendrix and Bohlen (2002, p. 802) stated that 
imported nonnative earthworms may be vectors for plant or animal 
pathogens or viruses, but the authors do not correlate this potential 
threat to the GPE. Although James (1995, p. 11) stated that predation 
on earthworms can be accentuated by tilling the soil and exposing 
earthworms to bird predators, the correlation to the GPE is uncertain 
as the GPE is believed to be an anecic species and therefore may be 
less likely to be exposed by tilling. Also, surveys to date have not 
found the GPE in agricultural fields, although we acknowledge the 
extent of those surveys has been limited. However, the species would 
not be exposed to increased predation caused by ongoing tillage if it 
does not occupy agricultural areas. In summary, we do not have any 
evidence indicating that disease or predation is a threat to the GPE 
such that listing under the Act is warranted.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    In our 2010 90-day finding (75 FR 42064; July 20, 2010), we 
determined the existing regulatory mechanisms may be inadequate to 
address potential threats to the GPE. The petitioners claim Federal, 
State, or local regulations do not specifically protect the GPE or its 
habitat. The Washington Department of Fish and Wildlife identifies the 
GPE as a species of concern (WDFW 2009, p. 1), although this status 
does not provide regulatory protection for the species. The petition 
states the Palouse Subbasin Management Plan (Gilmore 2004) includes 
objectives to protect and restore native grassland habitat within the 
Palouse subbasin, and increase wildlife habitat value on agricultural 
land, but is voluntary in nature and

[[Page 44560]]

does not provide regulatory mechanisms that protect the GPE or its 
habitat. Habitat conversion in the Palouse may still occur, as neither 
Latah County, Idaho, nor Whitman County, Washington, have ordinances or 
regulations to prevent native habitat conversion (Latah County Board of 
Commissioners 2010, pp. 1-27; Whitman County 2010, pp. 1-76). However, 
we do not have evidence that habitat loss is a threat (see Factor A 
discussion). The petition also acknowledges the existence of the U.S. 
Forest Service, Bureau of Land Management, U.S. Fish and Wildlife 
Service, Environmental Protection Agency, and National Oceanic and 
Atmospheric Administration (NOAA) Fisheries Memorandum of Understanding 
(MOU, USDA Forest Service et al. 2003), in which the agencies agreed to 
voluntarily utilize the scientific findings of the Interior Columbia 
Basin Strategy (CBS) to guide project implementation and to revise 
resource management plans. The petitioners state the MOU and CBS do not 
address the GPE or provide regulatory mechanisms for its protection 
(Petition, p. 15), and claim existing regulations are ineffective in 
reducing the importation of nonnative earthworm species, which present 
a threat to the GPE. However, the best available information does not 
indicate that exotic earthworms represent a threat to the GPE (see 
Factor E discussion).
    The U.S. Environmental Protection Agency (EPA) Office of Pesticide 
Programs evaluates which ingredients and which pesticide products can 
be used (registered) in the United States. The EPA evaluates the 
potential effects of pesticides on human health and the environment, 
conducts risk assessments, and works with companies to develop label 
instructions that ensure safety (see the National Pesticide Information 
Center at http://www.npic.orst.edu/reg.htm). One study found the use of 
pesticides at recommended rates had no detectable negative effects on 
earthworms in anecic or endogeic species (Simonsen et al., 2010, cited 
in Johnson-Maynard, 2010, in litt., p. 2). Therefore, the best 
available information indicates that the species is not threatened by 
the inadequacy of pesticide management.
    Surveys for the GPE have been limited, and there are significant 
uncertainties regarding the species' distribution and life history, as 
well as the diversity of habitat types where it may be found. This type 
of information is essential to credibly assess whether or not existing 
regulatory mechanisms are adequate to address potential threats to the 
species. While we acknowledge the regulations and plans described above 
do not provide specific protections for the GPE, we have no information 
to indicate this lack of specific protections is resulting in threats 
to the species. Therefore, we find that the available information does 
not support a conclusion that the inadequacy of existing regulatory 
mechanisms is a threat to the GPE.

Factor E. Other Natural or Manmade Factors Affecting the Species' 
Continued Existence

    The petitioners claim that the GPE is threatened by invasive, 
nonnative earthworms (Petition, p. 1). In a 3-year study of earthworms 
in the Palouse region of eastern Washington and Idaho, S[aacute]nchez-
de Le[oacute]n and Johnson-Maynard (2009, p. 1393) found a dominance of 
invasive, nonnative earthworms in both native and nonnative grasslands. 
Nonnative earthworms can invade new habitats, change the ecological 
soil functions, and displace native species (Hendrix and Bohlen 2002, 
p. 805; Petition, p. 16). Earthworm populations are dominated by 
nonnative earthworms in agricultural sites and native prairie remnants 
in the Palouse region (Fauci and Bezdicek 2002, p. 257; S[aacute]nchez-
de Le[oacute]n and Johnson-Maynard 2009, pp. 1396, 1399-1400; Petition, 
p. 16). Habitat conversion favors invasion of nonnative earthworm 
species that are better adapted to a disturbed or degraded environment 
(Petition, p. 16; James 1995, p. 5). James (1995, p. 5) stated that 
many exotic species occur in the Columbia Basin, possibly altering 
previously worm-free soils and nutrient cycling pathways, competing 
with native species, and generally modifying any processes linked to 
soil physical or chemical properties. He also stated that invasive 
earthworm species present a potential threat to the GPE, and described 
the loss of a deep-dwelling Illinois earthworm species as an example of 
this threat, although the particular study was not cited (James 2009, 
in litt., p. 2). Based on the limited information that was provided, we 
were unable to locate the study. James stated that although invasive 
earthworms do not always reduce or eliminate populations of indigenous 
worms, the invasion cannot help, and some species may be highly 
competitive with, a deeper-dwelling species like the GPE, while others 
may not (James 2009, in litt., p. 2). There are substantial weaknesses 
in extrapolating data from an Illinois earthworm species to the GPE, 
because we have no information that would indicate the responses would 
be similar. While the Service concludes that the GPE is anecic based on 
the best available information, there is some expert disagreement on 
the GPE's life-history strategy. However, it is unclear whether this 
matters in relation to invasion by nonnative earthworms, and James 
(2009 in litt. p. 2) did not present a scientific basis for using an 
Illinois species as a surrogate for the GPE.
    We agree that a correlation of decline and extirpation of some 
native earthworm species with the arrival of introduced earthworm 
species is well documented (Hendrix and Bohlen 2002, pp. 805-806; 
S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, pp. 1393-1394), 
although the cause may not always be direct. The causes of the declines 
of native species of earthworms are not documented, but theories center 
on ecosystem disturbance (Hendrix and Bohlen 2002, pp. 805-806) and 
competitive exclusion (James 2000, p. 8; Hendrix and Bohlen 2002, pp. 
805-806). In addition, James (2009, in litt., p. 2) noted that invasive 
earthworms do not always reduce or eliminate populations of indigenous 
earthworms. Depending on ecological requirements, some species may be 
highly competitive with a deeper-dwelling species like the GPE, and 
some not competitive, or there may be a combination of effects coupled 
with habitat modification. Co-occurrence of native and nonnative 
earthworm species is common both in disturbed and undisturbed 
ecosystems; however, it is not known if this is a transient or 
permanent state (Hendrix 2006, p. 1203). Ecosystem disturbance 
sufficient to degrade or destroy habitat for native species may be 
caused by the arrival of introduced worm species, or the arrival of 
introduced species may follow habitat degradation caused by other 
factors (Hendrix and Bohlen 2002, pp. 805-806). Nonnative earthworm 
invasions may depend on the degree of disturbance, competition with 
natives, and adaptability to site conditions (Hendrix and Bohlen 2002, 
p. 1203; S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, p. 
1394).
    In a 2003-2005 research effort in the Palouse region of 
southeastern Washington and northern Idaho, S[aacute]nchez-de 
Le[oacute]n and Johnson-Maynard (2009, pp. 1394-1395) compared four 
paired study sites representing native prairie remnants and CRP set-
aside lands. The study objective was to characterize and compare native 
and nonnative earthworm populations in two important grassland 
ecosystems within the Palouse region. Their results found that one 
invasive earthworm species, the southern worm (Aporrectodea 
trapezoides) comprised

[[Page 44561]]

90 percent of the total earthworm density in their study areas 
(S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, p. 1396). One 
GPE was collected at one of the four prairie remnant study sites. The 
authors suggested that because native earthworms are found in 
fragmented native habitats along with exotic earthworms, the GPE may be 
able to coexist with exotic species in Palouse prairie remnants. They 
indicated that further study would be required to determine whether the 
GPE is a resilient species based on its deep-burrowing behavior, or 
whether the results of their study demonstrate a species replacement 
process (S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, pp. 
1398).
    The rarity of native earthworms in their native prairie remnant 
study areas lends support to the researchers' theory that native 
earthworms are being replaced by nonnative earthworms, even in visibly 
intact remnants of fragmented habitats (S[aacute]nchez-de Le[oacute]n 
and Johnson-Maynard 2009, pp. 1398-1399). The researchers suggested 
Apporectodea trapezoides may compete with the GPE for food in upper 
layers of soil (S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, 
pp. 1398-1399), but could not exclude the possibility that the GPE did 
not historically occur in high densities within these prairie remnants 
because of their steep slope or high rock content, the very factors 
that prevented these areas from being plowed and preserved them as 
remnant prairie (S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 
2009, p. 1398). They acknowledged that these findings are inconsistent 
with other studies showing that native earthworms predominate in 
undisturbed or minimally disturbed grasslands (James 1991, pp. 2101-
2109; Callaham et al. 2003, pp. 1079-1093; Winsome et al. 2006, pp. 38-
53; in S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, pp. 
1397-1398).
    The researchers suggested that a combination of extensive habitat 
fragmentation in the Palouse region, low habitat quality of remaining 
prairie remnants, and possible competitive interactions with nonnative 
earthworms could have decimated GPE populations at their study sites 
(S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, p. 1398). They 
acknowledged that no information is available on GPE pre-agricultural 
density or distribution, but the description of the species as being 
abundant by Smith (1897) contrasts with the rarity of finding the 
earthworm today. They stated that this suggests a significant reduction 
in population size (S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 
2009, pp. 1394, 1399), but acknowledge their sampling methodology could 
have influenced the results. The hand-sorting sampling method is 
regarded as the best method to estimate abundance of most earthworm 
species, but is also known to underestimate the abundance of deep-
burrowing species. The researchers recommend the use of a combination 
of methods for future studies, including non-destructive alternatives 
such as electrical methods or extraction methods with chemicals of low 
toxicity that are more suited for deep-burrowing earthworm species 
(S[aacute]nchez-de Le[oacute]n and Johnson-Maynard 2009, p. 1399).
    The GPE's range is more extensive than previously known, survey 
efforts for this species have been limited, and effective survey 
protocols remain to be developed. We acknowledge conflicting opinions 
by earthworm researchers regarding the GPE's life-history strategy, 
which could influence how it interacts with exotic earthworms. However, 
we believe the prevailing evidence points to the GPE being a deep-
burrowing anecic species, based on observations in the field by 
scientists who appear to be most familiar with this particular species, 
and the report by Smith (1897, pp. 202-203) describing burrows 
extending to a depth of over 15 feet in new road cuts. Endogeic worms 
(which the petitioners believe the GPE to be) live in the upper layers 
of mineral soil, whereas anecic earthworms live in deep, semi-permanent 
burrows. The researchers S[aacute]nchez-de Le[oacute]n and Johnson-
Maynard also acknowledge that the hand-sorting sampling method (which 
has apparently been applied in most earthworm surveys) underestimates 
the abundance of deep-burrowing species. In addition, the limited 
evidence available does not lead to a reasoned scientific conclusion 
regarding competitive interactions between exotic earthworms and the 
GPE. In summary, we do not have evidence to support a conclusion that 
competition with exotic earthworms is a threat to the GPE.
Nonnative Plants
    The petitioners describe the existence of introduced annual grasses 
and noxious weeds in the Palouse region, including Poa pratensis 
(Kentucky bluegrass), crops, Bromus tectorum (cheatgrass), and 
Centaurea solstitialis (yellowstar-thistle) (Gilmore 2004, pp. 1-87), 
and state that it is likely these species do not provide the same 
quality and quantity of earthworm forage as native vegetation 
(Petition, p. 17). However, they did not provide any evidence to 
support this statement. There may be differences in nutritive value 
between weeds and native plants, and there may be differences in 
phenology (e.g., nonnative plants emerging at a different time than 
native plants), but it is unknown if this is important to the GPE. 
Invasive weed control in the Palouse is difficult (Jensen, 2010, in 
litt., p. 3; Nyamai 2009, pp. 6-7, 21-22). Native plant communities in 
the Palouse are susceptible to invasion by nonnative plants (Gilmore 
2004, pp. 1-26; James 2000, p. 8); domination of deep-soil sites by 
Kentucky bluegrass is common, and in shallow soils cheatgrass and 
yellowstar-thistle weeds compete with native grasslands. McGregor 
(1982, pp. 124-125) commented that nonnative weeds, including 
cheatgrass, have been present in the Palouse region since the 1890s. 
The Draft Palouse Subbasin Management Plan (Gilmore 2004, pp. 1-86) 
states that exotic weed invasions are possibly the greatest threat 
facing the grasslands and shrublands of the arid and semiarid West 
today, and species-rich ecosystems are being converted to monotonous 
weedlands as aggressive weeds replace native plants and degrade habitat 
for wildlife.
    There are significant scientific uncertainties regarding the 
distribution and life history of the GPE, and the range of habitat 
types it occupies is unknown. Although there have been some studies 
relevant to nonnative plant invasion and conversion of native habitats 
and ecosystems, we are unaware of any scientific studies or other data 
that would allow an extrapolation of these observations to the GPE. 
Accordingly, we have no information to indicate that the introduction 
of nonnative plants represents a threat to the species.
Climate Change
    The petitioners noted that, because Fender and McKey-Fender (1990, 
p. 366) describe annual precipitation as a parameter of GPE habitat, it 
is likely that changing weather patterns caused by global warming will 
impact this species' habitat and distribution (Petition, p. 17). This 
citation in fact defines the lower limit of precipitation tolerated by 
argilophilini worm species to be about 15 in (38 cm) annually, which 
the authors characterize as being ``about the edge of moist forests in 
our area, although the range of Driloleirus americanus extends into 
treeless areas.'' Although the petition expresses a concern about 
future climate change and its effects on the GPE, it did not present 
information or data in this regard.
    The Service evaluated information available in our files and 
queried other available information related to this potential threat. 
Lawler and Mathias

[[Page 44562]]

(2007, pp. 19-20) investigated possible climate change impacts to 
vascular plants, stating that plants may mature earlier, creating 
potential mismatches between pollinators and plants, parasites and 
hosts, and herbivores and food sources; increased summer temperatures 
and decreased summer precipitation may lead to changes in distribution 
of some plant species; sagebrush steppe and grasslands may contract, 
while dry forests and woodlands expand; and plant distribution changes 
will depend in part on plant water-use efficiencies. According to the 
United Nations Framework Convention on Climate Change (2010, p. 1), 
plant growth may benefit from fewer freezes and chills, but some crops 
may be damaged by higher temperatures, particularly if combined with 
water shortages. Certain weeds may expand their range into higher-
latitude habitats. Higher levels of carbon dioxide should stimulate 
photosynthesis in certain plants, in principle. This is particularly 
true for C3 plants (named for their carbon fixation pathway) because 
increased carbon dioxide tends to suppress their photo-respiration. C3 
plants make up the majority of species globally, especially in cooler 
and wetter habitats, and include most crop species, such as wheat, 
rice, barley, cassava, and potato.
    It is difficult to predict how or if future changes in growth or 
distribution of vegetation resulting from climate change will affect 
local conditions for weeds, native vegetation, or both, or to predict 
how such changes would affect earthworms. Earthworm mortality can 
result from extreme temperatures, and the upper lethal temperature for 
different earthworm species is lower than for other invertebrates 
((Edwards and Bohlen 1996, p. 146) (e.g., 28 [deg]C (82 [deg]F) for 
Lumbricus terrestris; 37 to 37.75 [deg]C (98.6 to 100 [deg]F) for 
Pheretima californica (Schread 1952, as referenced in Edwards and Lofty 
1977, pp. 156-157)). Earthworms tolerate higher temperatures by 
migrating, or burrowing deeper, but must still be able to feed on the 
surface or the top layers of the soil.
    The petition did not present any specific information, and we are 
unaware of any studies, that would facilitate an evaluation of the 
extent to which the GPE may be affected by: (1) Increased air 
temperatures or soil changes; (2) earlier seasonality of plant 
production; or (3) changes in plant distribution. Climate change models 
used in the Intergovernmental Panel on Climate Change Fourth Assessment 
Report project increased air annual temperatures in the Pacific 
Northwest of, on average, 1.1 [deg]C (2.0 [deg]F) by the 2020s, 1.8 
[deg]C (3.2 [deg]F) by the 2040s, and 2.9 [deg]C (5.3 [deg]F) by the 
2080s, compared to 1970 and 1999 (averaged across all climate models); 
however, increased air temperature does not necessarily correlate with 
increased surface or soil temperatures. Projected changes in annual 
precipitation averaged over all models are small (+1 to +2 percent), 
but some models project an enhanced seasonal precipitation cycle with 
changes toward wetter autumns and winters, and drier summers (Littell 
et al., 2009, p. 1). In the Pullman, Washington, area, baseline annual 
precipitation is estimated at 21.1 in (53.6 cm); models projecting to 
2080 do not project annual precipitation below 15 in (38.1 cm) under 
any scenarios (Climate Impacts Group 2009, pp. 197-198). Fifteen inches 
(38.1 cm) of annual precipitation has been suggested as the lower limit 
of precipitation tolerated by argilophilini worm species, such as the 
GPE (Fender and McKey-Fender 1990, p. 366).
    The impact of climate change on selected but economically 
significant crops in eastern Washington was predicted to be generally 
mild in the short term (i.e., the next two decades), but increasingly 
detrimental with time (potential yield losses reaching 25 percent for 
some crops by the end of the century). The projected elevated carbon 
dioxide (CO2) was expected to provide significant mitigation 
of climate change and its effects, and in fact result in important 
yield gains for some crops (Littell et al. 2009, p. 212), and it is 
likely that some native or nonnative plants would be similarly 
increased, potentially increasing the forage base for GPE.
    Existing climate change projections are inadequate to allow a 
prediction regarding whether or how future climate change will impact 
the GPE or its habitat. This is further complicated by the significant 
uncertainties that exist regarding the species' distribution, biology, 
and habitat needs. However, given that the prevailing evidence 
indicates the species is anecic based on the results of survey efforts 
and the description of deep burrows associated with the species (Smith 
1897, pp. 202-203), it is reasonable to conclude the species' deep-
burrowing behavior will limit its exposure and increase its 
adaptability to increased soil temperatures. It is unclear how or 
whether drier summers would impact the GPE, or whether vegetation 
changes would impact the GPE. Therefore, based on the best available 
information, we conclude that climate change does not constitute a 
threat to the species.
Summary of Factor E
    Although the decline and extirpation of some native earthworm 
species with the arrival of introduced earthworm species has been well 
documented, survey efforts for this species have been limited and 
effective survey protocols remain to be developed. In addition, there 
are conflicting opinions by earthworm researchers regarding the GPE's 
life history strategy, which could influence how it interacts with 
exotic earthworm species. Native plant communities in the Palouse 
bioregion are susceptible to invasion by nonnative plants, although we 
are unaware of any studies that correlate nonnative plant invasion and 
conversion of GPE habitat. The petition stated that future climate 
change could affect the GPE, although no supporting information or data 
was presented. Our examination of this concern has determined that 
existing climate change projections are inadequate to predict how 
future climate change may impact the GPE, which is further complicated 
because of the significant uncertainties regarding the species' 
distribution, life history, and the range of habitat types it occupies. 
In summary, there is no scientific evidence to support a conclusion 
that the GPE is threatened by competitive interactions with exotic 
earthworms, the conversion of habitat by nonnative plants, or future 
climate change.
Summary of Factors
    A summary of our conclusions for each of the five factors is found 
in Table 2. More specific information for each threat considered under 
the five factors is available in the Summary of Information Pertaining 
to the Five Factors section above.

  Table 2--Section 4(a)(1) Listing Factors Summary of Potential Threats
                               Considered
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Factor A..........................  Habitat loss and fragmentation: The
                                     current or historical population,
                                     distribution, and range of the GPE
                                     is unknown; the habitats used by
                                     the GPE are more diverse than
                                     suggested by petitioners; survey
                                     efforts have been limited and
                                     sampling protocols remain to be
                                     developed to improve detection
                                     capabilities; there is no evidence
                                     with which to correlate current or
                                     future habitat loss with GPE
                                     abundance or status.

[[Page 44563]]

 
                                    Soil characteristics: There is no
                                     information with which to link soil
                                     disturbance with GPE presence or
                                     absence.
                                    Soil compaction: There is no
                                     evidence that compaction is
                                     occurring in GPE habitat or that
                                     compaction would trigger a negative
                                     response.
                                    Soil chemistry: Earthworm responses
                                     to soil pH vary depending on the
                                     species, location, and life history
                                     strategy; there is insufficient
                                     information with which to establish
                                     cause-effect relationship that
                                     might be limiting to GPE; and there
                                     is no information that Palouse
                                     region soils are acidic enough to
                                     negatively affect earthworms.
                                    Tillage and agriculture: There is no
                                     information indicating the GPE is
                                     exposed to these activities, and no
                                     GPEs have been documented in
                                     agricultural areas.
                                    Grazing: There is no information
                                     with which to correlate GPE
                                     distribution and grazing areas; the
                                     species' range is unknown and
                                     surveys have been limited; grazing
                                     can sometimes benefit earthworms;
                                     and larger species like the GPE may
                                     be less impacted than smaller
                                     species.
                                    Chemical applications: Chemicals are
                                     applied in agricultural areas--the
                                     GPE has not been documented in
                                     agricultural areas; the available
                                     information is inadequate to
                                     determine how and whether
                                     pesticides impact soils occupied by
                                     the GPE; some studies indicate
                                     anecic species are less susceptible
                                     to pesticides; the GPE has wider
                                     range and occurs in more diverse
                                     habitats than previously known; and
                                     there is limited information on
                                     pesticide applications in known GPE
                                     areas.
                                    Urbanization and rural development:
                                     There are significant uncertainties
                                     regarding GPE distribution, range,
                                     population trends and extent of
                                     habitat types used; and there is no
                                     evidence that correlates
                                     urbanization and rural development
                                     with threats to the GPE.
                                    Forest management: Information is
                                     insufficient to determine the
                                     extent of forested habitat occupied
                                     by the GPE or where it occurs in
                                     forested habitat; and there is no
                                     information available regarding how
                                     the GPE would respond to differing
                                     types of forest management
                                     activities.
Factor B..........................  Mortality resulting from scientific
                                     collections: Earthworms are not
                                     targets for collection by
                                     hobbyists; some mortality is
                                     expected from scientific
                                     collection, but we have no basis to
                                     conclude that removal of a few
                                     individuals for this purpose would
                                     have population-level impacts.
Factor C..........................  Disease: We do not have any evidence
                                     indicating disease is a threat to
                                     the GPE.
                                    Predation resulting from exposure
                                     during tilling operations: GPEs
                                     have not been observed in
                                     agricultural areas; the GPE is
                                     believed to be an anecic species,
                                     which would be less likely to be
                                     exposed by tilling, even if it were
                                     to occupy agricultural areas.
Factor D..........................  Non-regulatory programs and
                                     measures: Although the WDFW
                                     considers the GPE to be a species
                                     of concern and the USFS, FWS, NOAA,
                                     BLM, EPA developed a MOU agreeing
                                     to use scientific findings of the
                                     CBS to guide management plans,
                                     these are voluntary measures and
                                     have no regulatory affect;
                                    EPA pesticide regulations: The EPA
                                     regulates use of pesticide in the
                                     U.S.; one study found the use of
                                     pesticides at recommended rates had
                                     no detectable negative effects on
                                     anecic or endogeic earthworms; and
                                     having a better understanding of
                                     GPE distribution, life history, and
                                     diversity of habitat used is
                                     essential to credibly assess
                                     whether existing regulatory
                                     mechanisms are inadequate.
Factor E..........................  Nonnative invasive earthworms: The
                                     co-occurrence of native and
                                     nonnative earthworms is common in
                                     both disturbed and undisturbed
                                     ecosystems, and the limited
                                     evidence available does not lead to
                                     a reasoned scientific conclusion
                                     regarding competitive interactions
                                     between the GPE and exotic
                                     earthworms;
                                    Nonnative plants: Significant
                                     scientific uncertainties exist
                                     regarding GPE distribution, life
                                     history, and range; the best
                                     available information does not
                                     allow an extrapolation of nonnative
                                     plant invasion to GPE threats.
                                    Climate change: The best available
                                     information is insufficient to
                                     determine the extent to which the
                                     GPE might be affected by increased
                                     air temperatures or soil changes,
                                     earlier seasonality of plant
                                     production, or changes in plant
                                     distribution; fifteen inches of
                                     annual precipitation was suggested
                                     as lower limit of precipitation
                                     tolerated by species such as the
                                     GPE, although models projecting out
                                     to 2080 do not show annual
                                     precipitation in the Pullman, WA
                                     vicinity falling below 15 inches
                                     under any scenarios; and
                                     significant uncertainties regarding
                                     the GPE's distribution, biology,
                                     and habitat needs frustrate efforts
                                     to draw parallels between climate
                                     change and the species' response.
------------------------------------------------------------------------
A: Present or threatened destruction, modification, or curtailment of
 habitat or range;
B: Overutilization for commercial, recreational, scientific, or
 educational purposes;
C: Disease or predation;
D: Inadequacy of existing regulatory mechanisms;
E: Other natural or manmade factors.
------------------------------------------------------------------------

Finding

    As required by the Act, we considered the five factors in assessing 
whether the GPE is endangered or threatened throughout all or a 
significant portion of its range. We examined the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by the GPE. We reviewed the petition, information 
available in our files, and other available published and unpublished 
information, and we consulted with the most qualified GPE experts and 
queried universities, State agencies, conservation districts, and other 
entities. In considering what factors might constitute threats, we must 
look beyond the mere exposure of the species to the factor to determine 
whether the species responds to the factor in a way that causes actual 
impacts to the species. If there is exposure to a factor, but no 
response, or only a positive response, that factor is not a threat. If 
there is exposure and the species responds negatively, the factor may 
be a threat and we then attempt to determine how significant a threat 
it is. If the threat is significant, it may drive or contribute to the 
risk of extinction of the species such that the species warrants 
listing as endangered or threatened as those terms are defined by the 
Act. This does not necessarily require empirical proof of a threat. The

[[Page 44564]]

combination of exposure and some corroborating evidence of how the 
species is likely impacted could suffice. The mere identification of 
factors that could impact a species negatively is not sufficient to 
compel a finding that listing is appropriate; we require evidence that 
these factors are operative threats that act on the species to the 
point that the species meets the definition of endangered or threatened 
under the Act.
    The analysis of threats (the five factors) to determine if the 
status of GPE meets the definition of endangered or threatened was 
particularly challenging, because the range of the species appears to 
be greater than it was originally thought to be. In addition to the 
Palouse area prairie, the species has been documented in dry forest 
habitat on the east slope of the Cascades. Survey effort for this 
species has been low, especially outside of the Palouse grasslands, and 
appropriate survey methods remain to be developed. In addition, the 
life history of the GPE is not completely understood. There is still 
some scientific debate regarding whether the GPE is an anecic or 
endogeic species, although the most recent field observations and 
prevailing scientific evidence indicates it is a deep-burrowing anecic 
species (Johnson-Maynard 2010, p. 2), which would result in a different 
exposure to threats than if it were an endogeic species. There is no 
scientific basis to conclude that any of the activities identified as 
threats by the petitioners are, in fact, threats to the GPE.
    Based on our review of the best available scientific and commercial 
information pertaining to the five factors, we find that the threats 
are not of sufficient imminence, intensity, or magnitude to indicate 
that the GPE is in danger of extinction (endangered), or likely to 
become endangered within the foreseeable future (threatened), 
throughout all of its range. Therefore, we find that the GPE does not 
meet the definition of an endangered or threatened species throughout 
its range.

Distinct Vertebrate Population Segment and Significant Portion of the 
Range Analysis

    After assessing whether the species is endangered or threatened 
throughout its range, we next consider whether a distinct vertebrate 
population segment (DPS) or whether any significant portion of the GPE 
range meets the definition of endangered or is likely to become 
endangered in the foreseeable future (threatened), in accordance with 
the Service's Policy Regarding the Recognition of Distinct Vertebrate 
Population Segments under the Endangered Species Act (61 FR 4722, 
February 7, 1996). Because the GPE is not a vertebrate species, the 
Distinct Vertebrate Population Segment policy is not applicable to this 
finding.

Significant Portion of the Range

    Having determined that the GPE does not meet the definition of an 
endangered or threatened species, we must next consider whether there 
are any significant portions of the range where the GPE is in danger of 
extinction or is likely to become endangered in the foreseeable future. 
Because of significant uncertainties regarding the range of the GPE, 
the limited survey efforts, and the paucity of information regarding 
its life history, there is nothing to suggest that threats are 
disproportionately acting on any portion of the species' range, such 
that the species is at risk of extinction now or in the foreseeable 
future. Therefore, we find that listing the GPE as an endangered or 
threatened species is not warranted throughout all or a significant 
portion of its range. The designation of critical habitat for this 
species as requested by the petitioner is not appropriate, based on our 
determination that the species does not warrant listing under the Act.
    The Service continues to be interested in the status of this unique 
species. We request that you submit any new information concerning the 
status of, or threats to, the GPE to our Washington Fish and Wildlife 
Office (see ADDRESSES) whenever it becomes available. New information 
will help us monitor the GPE and encourage its conservation.

References Cited

    A complete list of references cited is available on the Internet at 
http://www.regulations.gov and upon request from the Washington Fish 
and Wildlife Office (see ADDRESSES).

Author(s)

    The primary authors of this notice are the staff members of the 
Washington Fish and Wildlife Office.

Authority

    The authority for this section is section 4 of the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: July 12, 2011.
David Cottingham,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-18645 Filed 7-25-11; 8:45 am]
BILLING CODE 4310-55-P