[Federal Register Volume 71, Number 17 (Thursday, January 26, 2006)]
[Proposed Rules]
[Pages 4341-4344]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-943]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17


Endangered and Threatened Wildlife and Plants; 90-day Finding on 
a Petition To List the American Dipper in the Black Hills of South 
Dakota as Threatened or Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list the distinct vertebrate population 
segment (DPS) of American dipper (Cinclus mexicanus unicolor) in the 
Black Hills of South Dakota as threatened or endangered under the 
Endangered Species Act of 1973, as amended (Act). We find that the 
petition and other readily available information do not provide 
substantial scientific or commercial information indicating that 
listing the American Dipper in the Black Hills of South Dakota may be 
warranted. This finding is based on our determination that the American 
Dipper in the Black Hills of South Dakota does not constitute a valid 
DPS and, therefore, cannot be considered a listable entity pursuant to 
section 3(15) of the Act. Therefore, we will not initiate a status 
review to determine if listing this species is warranted in response to 
this petition. However, the public may submit to us new information 
concerning the species, its status or threats to it at any time.

DATES: The finding announced in this document was made on January 19, 
2006.

ADDRESSES: Information, data, comments, or questions concerning this 
petition and our finding should be submitted to the Field Supervisor, 
South Dakota Ecological Services Office, U.S. Fish and Wildlife 
Service, 420 South Garfield Avenue, Suite 400, Pierre, South Dakota 
57501. The petition, supporting data, and comments will be available 
for public inspection, by appointment, during normal business hours, at 
the above address.

FOR FURTHER INFORMATION CONTACT: Pete Gober, Field Supervisor, South 
Dakota Ecological Services Office at the above address (telephone 605-
224-8693; facsimile 605-224-9974).

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(A) of the Act (16 U.S.C. 1531 et seq.), requires 
that we make a finding on whether a petition to list, delist, or 
reclassify a species presents substantial scientific or commercial 
information indicating that the petitioned action may be warranted. We 
are to base this finding on information provided in the petition and 
other information that is readily available to us (e.g., in our files). 
To the maximum extent practicable, we are to make this finding within 
90 days of our receipt of the petition, and publish our notice of this 
finding promptly in the Federal Register.
    Our standard for substantial scientific information within the Code 
of Federal Regulations (CFR) with regard to a 90-day petition finding 
is ``that amount of information that would lead a reasonable person to 
believe that the measure proposed in the petition may be warranted'' 
(50 CFR 424.14(b)). If we find that substantial scientific information 
was presented, we are required to commence a review of the status of 
the species.
    In making this finding, we relied on information provided by the 
petitioners and information in our files, and evaluated that 
information in accordance with 50 CFR 424.14(b). Our process of coming 
to a 90-day finding under section 4(b)(3)(A) of the Act and Sec.  
424.14(b) of our regulations is limited to a determination of whether 
the information in the petition meets the ``substantial scientific 
information'' threshold.
    We do not conduct additional research to make a 90-day finding, nor 
do we subject the petition to rigorous critical review. Rather, as the 
Act and regulations contemplate, in coming to a 90-day finding, we 
acknowledge the petitioner's sources and characterizations of the 
information unless we have specific information to the contrary.
    Our 90-day findings consider whether the petition states a 
reasonable case for listing on its face. Thus, our finding expresses no 
view as to the ultimate issue of whether the species should be listed. 
We reach a conclusion on that

[[Page 4342]]

issue only after a more thorough review of the species' status.

Petition

    On March 28, 2003, we received a petition dated March 15, 2003, 
requesting that we list the distinct population segment (DPS) of 
American dipper (Cinclus mexicanus unicolor) in the Black Hills of 
South Dakota as threatened or endangered under the Act, and for the 
designation of critical habitat for that DPS. In addition, the petition 
requested emergency listing of the DPS. The petition, submitted by the 
Biodiversity Conservation Alliance, Center for Native Ecosystems, 
Native Ecosystems Council, Prairie Hills Audubon Society and Jeremy 
Nichols, was clearly identified as a petition for a listing rule, and 
it contained the names, signatures, and addresses of the requesting 
parties. Included in the petition was supporting information regarding 
the species' taxonomy and ecology, historical and current distribution, 
present status, and potential causes of decline.
    We acknowledged the receipt of the petition in a letter to Mr. 
Jeremy Nichols, dated May 20, 2003. In that letter, we advised the 
petitioners that emergency listing was not justified and that, due to 
funding constraints, we would not be able to begin processing the 
petition in a timely manner.
    On July 21, 2003, we received a Notice of Intent to sue from the 
petitioners contending that the Service had violated the ESA by failing 
to make a timely 90-day finding on the petition to list a DPS of the 
American dipper.
    On August 20, 2004, the petitioners filed a complaint in Federal 
District Court against the Secretary of the Interior and the Service 
for failure to make a 90-day finding under section 4 of the ESA. In a 
stipulated settlement agreement, we agreed to submit a 90-day finding 
to the Federal Register by January 20, 2006 [Black Hills Dipper, et al. 
v. Norton et al. (04-cv-1293 (DDC))]. The settlement agreement was 
signed and adopted by the District Court for the District of Columbia 
on January 24, 2005. This notice constitutes our 90-day finding for the 
petition to list a DPS of the American dipper in the Black Hills of 
South Dakota as endangered or threatened, pursuant to the agreement.

Species Information

    The American dipper is a small, gray passerine bird that inhabits 
western Canada and the western United States, including the Black Hills 
(Pettingill and Whitney 1965; Anderson 2002). The American dipper 
utilizes permanent, clean, cold, and swift mountain streams (Kingery 
1996; Tyler and Ormerod 1994; Price and Bock 1983; Feck 2002) with 
abundant and healthy populations of benthic macroinvertebrate, the 
dipper's prey (Price and Bock 1983; Kingery 1996; Tyler and Ormerod 
1994; Ealey 1977). Dippers are usually found in streams with rock, 
sand, and rubble substrates, which also are associated with the highest 
abundance of aquatic invertebrates. American dippers establish linear 
territories along a river in early spring (Kingery 1996). They remain 
in or near their territories most of the year, depending upon the 
availability of open water. Dipper nest sites can be found on 
streamside rock cliffs, waterfalls, on large rocks in midstream, or 
under bridges (Kingery 1996).
    There are few records of American dippers making long distance 
flights, and these records do not substantiate that these movements 
contribute to the establishment of new populations. No instances of 
long distance dispersal of dippers between the Black Hills and the next 
nearest populations of American dipper to the west in the Big Horn 
Mountains of north-central Wyoming and the Laramie Range of east-
central Wyoming have been documented.

Distribution, Abundance, Trends

    The American dipper is at the eastern edge of its range in the 
Black Hills. The dipper is a permanent year-round resident of the Black 
Hills and has historically been known to inhabit nearly all permanent, 
fast-flowing streams in the area (Pettingill and Whitney 1965). The 
species is not known to disperse or migrate long distances; the extent 
to which it moves to any degree between the geographically separated 
areas that it occupies is undocumented (Tyler and Ormerod 1994). The 
dipper population in the Black Hills is isolated from other populations 
by geographical barriers to dispersal in the form of extensive 
grasslands, poor quality stream habitat, and the lack of water 
connections to dipper populations existing west of the Black Hills 
(Backlund 2001).
    Verified historic American dipper reports have been recorded on six 
streams and/or their tributaries in the Black Hills: French Creek; 
Rapid Creek; Box Elder Creek; Elk Creek; Whitewood Creek; and Spearfish 
Creek (Backlund 2001). Other streams are unable to support self-
sustaining populations of dipper due to habitat degradation, erratic 
water flows, loss of water flow, poor water quality, and other impacts 
(Backlund 2001). Currently, nesting dippers can be found on only two 
streams in the Black Hills--Spearfish Creek and Whitewood Creek.
    Dipper nest surveys in the Black Hills were started in 1993 and 
became more extensive from 2003 to 2005. The lowest number of dippers 
reported on Spearfish Creek was 10 in 1997, with only 2 nests found 
(Backlund 2001). In 2004, the number of dippers reported on Spearfish 
Creek was approximately 49, with 31 nest attempts (Lovett 2004). In 
2004, Whitewood Creek had 12 adults observed and 7 known nest attempts 
(Lovett 2004).

Distinct Vertebrate Population Segment

    The petitioners have asked us to consider listing a DPS of the 
American dipper in the Black Hills of South Dakota. Under the Act, we 
can consider for listing any species, subspecies, or DPS of any species 
of vertebrate fish or wildlife that interbreeds when mature, if 
information is substantial to indicate that such action may be 
warranted. To implement the measures prescribed by the Act and its 
congressional guidance, we developed a joint policy with the National 
Oceanic and Atmospheric Administration entitled Policy Regarding the 
Recognition of Distinct Vertebrate Population Segments under the Act 
(61 FR 4722; February 7, 1996) (DPS Policy). Under the DPS policy, we 
must consider three elements in making our decision whether an entity 
qualifies as a DPS that warrants listing as endangered or threatened 
under the ESA. The three elements are: (1) The population segment's 
discreteness in relation to the remainder of the species to which it 
belongs; (2) the population segment's significance to the species to 
which it belongs; and (3) the population segment's conservation status 
in relation to the Act's standards for listing (i.e., when treated as 
if it were a species, is the population segment endangered or 
threatened?). Following is our evaluation of these elements in relation 
to the petitioned entity (the American dipper in the Black Hills of 
South Dakota).

Discreteness

    The DPS policy states that a population segment of a vertebrate 
species may be considered discrete if it satisfies either one of the 
following two conditions: It must be markedly separated from other 
populations of the same taxon as a consequence of physical, 
physiological, ecological, or behavioral factors, or it must be 
delimited by international governmental boundaries within which 
significant differences in control of exploitation, management of 
habitat conservation status or regulatory mechanisms exist

[[Page 4343]]

that are significant in light of section 4(a)(1)(D) of the Act.

Information Provided in the Petition

    Substantial information is presented in the petition to indicate 
that the Black Hills population may be markedly separated from other 
populations of the American dipper as a consequence of physical 
factors. The Black Hills is an isolated mountain range located within 
the plains of western South Dakota and northeastern Wyoming (Raventon 
1994). The Great Plains, which entirely surrounds the Black Hills, 
creates a major physical barrier separating the Black Hills American 
dipper from other Rocky Mountain populations to the west (Hall et al. 
2002). The Bighorn Mountains, approximately 150 to 200 miles (mi) (241 
to 322 kilometers (km)) to the west, is the closest mountain range to 
the Black Hills (Froiland 1990). The expanse of grassland separating 
the Black Hills from other mountain ranges is incapable of supporting 
American dippers and represents a significant barrier to dispersal 
(Backlund 2001; Voelker 2002). The streams and rivers of the Great 
Plains are described as typically silt-laden, turbid, alkaline, and 
subject to erratic flows which precludes their use by dippers (Smith 
and Hubert 1989).
    Information in the petition, as supported by information readily 
available in our files, suggests that there is a substantial physical 
isolation of the Black Hills population of the American dipper. 
Therefore, the petition presents substantial information indicating 
that the Black Hills population of the American dipper meets a 
condition for discreteness under our DPS policy. The Black Hills 
population of the American dipper is not delimited by international 
governmental boundaries within which significant differences in control 
of exploitation, management of habitat conservation status or 
regulatory mechanisms exist that are significant in light of section 
4(a)(1)(D) of the ESA.

Significance

    Pursuant to our DPS policy, in addition to our consideration that a 
population segment is discrete, we further consider its biological and 
ecological significance to the taxon to which it belongs, within the 
context that the DPS policy be used ``sparingly'' while encouraging the 
conservation of genetic diversity (61 FR 4722; February 7, 1996). This 
consideration may include, but is not limited to: (1) Evidence of the 
persistence of the discrete population segment in an ecological setting 
that is unique for the taxon; (2) evidence that loss of the population 
segment would result in a significant gap in the range of the taxon; 
(3) evidence that the population segment represents the only surviving 
natural occurrence of a taxon that may be more abundant elsewhere as an 
introduced population outside its historical range; and (4) evidence 
that the discrete population segment differs markedly from other 
populations of the species in its genetic characteristics.

Information Provided in the Petition

    a. Persistence of the population segment in an ecological setting 
that is unique for the taxon.
    The American dipper occupies permanent, clean, cold, and swift 
mountain streams throughout the western half of North America, 
including the Black Hills (Kingery 1996). The petition contends that 
the streams in the Black Hills inhabited by dippers may be a unique 
ecological setting because the Black Hills themselves are a unique 
ecosystem. We recognize that the Black Hills have many unique 
ecological features, but information readily available in our files 
(e.g., Kingery 1996) indicates that these mountain ecosystems share 
commonalities such as clean, cold, swift mountain streams with suitable 
substrate that provide the habitats for invertebrate species used by 
dippers. In that respect, the Black Hills are similar to other western 
mountain ecosystems.
    In addition, the petitioners claim that Black Hills streams have 
features that make them ecologically unique. Streams throughout the 
Rocky Mountains vary in many features, including elevation, gradient, 
substrate, parent geological material, riparian vegetation, etc., such 
that virtually every stream could be considered ``unique.'' Information 
readily available in our files (e.g., Kingery 1996) indicates that the 
key features of Black Hills streams used by dippers--cold temperatures, 
good water quality, suitable substrate, and swift flow--are the same 
key features of dipper-utilized streams elsewhere throughout the Rocky 
Mountains. Accordingly, we do not believe the petition presents 
substantial information that the clean, cold swift streams of the Black 
Hills occupied by dippers are an ecological setting that is unique for 
this subspecies.
    b. Loss of the population segment would result in a significant gap 
in the range of taxon.
    The petition claims that the Black Hills dipper population is at 
the eastern edge of its global distribution, and its loss would result 
in a significant gap in the range of the dipper. Information readily 
available in our files (e.g., Kingery 1996) states that the American 
dipper's breeding range extends from western Alaska eastward across 
northcentral Alaska; southward along the Pacific Coast and throughout 
the Rocky Mountains into New Mexico. They are absent from the Great 
Basin area except for scattered populations. The range includes 
mountain streams in an area that is approximately 5,000 km from north 
to south and approximately 1,800 km from west to east at its widest 
point. Within that range, there are thousands of suitable streams and 
tens of thousands of kilometers of occupied streams. The Black Hills 
dipper population occupies two streams that represent less than 80 km 
of occupied stream habitat. The dipper-occupied streams in the Black 
Hills are on the eastern edge of the overall dipper's range and if lost 
would not create a gap in the overall species range with other dipper 
populations. The mountain streams of the Black Hills provide the 
easternmost habitat for the American dipper. We conclude that the 
petition does not present substantial information that loss of the 
population segment would result in a significant gap in the range of 
taxon.
    c. The population segment represents the only surviving natural 
occurrence of a taxon that may be more abundant elsewhere as an 
introduced population outside its historical range.
    The petition does not address this factor. The American dipper 
survives naturally throughout much of western North America.
    d. The discrete population segment differs markedly from other 
populations of the species in its genetic characteristics.
    The petition does not address this factor. We are aware that a 
genetic analysis is being conducted to determine whether the Black 
Hills population of the American dipper is genetically distinct from 
other American dipper populations in North America (C. Anderson, Black 
Hills State University, pers. comm. 2005). To date, the research has 
analyzed samples from 6 populations (Black Hills, SD; Bighorns, WY; and 
four locations in west central Montana and east central Idaho). 
Preliminary information from this research suggests that genetic 
differences may exist among the dipper populations studied. However 
these results are too preliminary to determine the significance of the 
Black Hills population of American dipper to the taxon as a whole.

Finding

    We have reviewed the information presented in the petition, and 
have

[[Page 4344]]

evaluated that information in relation to information readily available 
in our files. On the basis of our review, we find that the petition 
does not present substantial scientific or commercial information to 
indicate that listing the American dipper in the Black Hills of South 
Dakota may be warranted. This finding is based on the lack of 
substantial scientific evidence to indicate that the American dipper in 
the Black Hills of South Dakota constitutes a valid DPS. Although the 
population is discrete, neither the information in the petition nor the 
information readily available in our files constitutes substantial 
scientific information that the Black Hills dipper population is 
significantly unique in relation to the remainder of the taxon. 
Therefore, we conclude that the American dipper in the Black Hills of 
South Dakota is not a listable entity pursuant to section 3(15) of the 
ESA. We will not be commencing a status review in response to this 
petition. However, we will continue to monitor the taxon's population 
and status and trends, potential threats, and ongoing management 
actions that might be important with regard to the conservation of the 
American dipper across its range. We encourage interested parties to 
continue to gather data that will assist with these conservation 
efforts. New information should be submitted to the Field Supervisor, 
South Dakota Ecological Services Office (see ADDRESSES).
    The petitioners also request that critical habitat be designated 
for this species. The petition does not present substantial information 
that the American dipper is a DPS so we need not address the 
designation of critical habitat at this time.

References Cited

    A complete list of all references is available upon request from 
the Field Supervisor (see ADDRESSES).

Author

    The primary authors of this document are staff at the South Dakota 
Ecological Services Office (see ADDRESSES).

Authority

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

    Dated: January 19, 2006.
Thomas O. Melius,
Acting Director, Fish and Wildlife Service.
[FR Doc. E6-943 Filed 1-25-06; 8:45 am]
BILLING CODE 4310-55-P