[Federal Register Volume 59, Number 63 (Friday, April 1, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-7834]


[[Page Unknown]]

[Federal Register: April 1, 1994]


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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 Remove the Mexican Spotted Owl From the List of 
Endangered and Threatened Wildlife

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of petition finding.

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SUMMARY: The U.S. Fish and Wildlife Service (Service) announces a 90-
day finding for a petition to remove the Mexican spotted owl (Strix 
occidentalis lucida) from the List of Endangered and Threatened 
Wildlife. The Service has determined that the petition did not present 
substantial scientific or commercial information indicating that 
delisting the Mexican spotted owl may be warranted.

DATES: The finding announced in this notice was made on March 25, 1994.

ADDRESSES: Information, comments, or questions concerning the 
petitioned action may be submitted to the Listing Coordinator, 
Southwest Region, U.S. Fish and Wildlife Service, P.O. Box 1306, 
Albuquerque, New Mexico 87103; or the Field Supervisor, Suite D, 3530 
Pan American Highway NE, Albuquerque, New Mexico 87107. The petition, 
finding, supporting data, and comments will be available for public 
inspection, by appointment, during normal business hours at the latter 
address.

FOR FURTHER INFORMATION CONTACT: Steve Spangle, Listing Coordinator, at 
the above Regional Office address (505/766-3972).

SUPPLEMENTARY INFORMATION:

Background

    On December 22, 1989, the Service received a petition (listing 
petition) to list the Mexican spotted owl (Strix occidentalis lucida) 
(MSO) under the Endangered Species Act of 1973, as amended (16 U.S.C. 
1531 et seq.) (Act). The Service published a proposed rule to list the 
subspecies as threatened on November 4, 1991 (56 FR 56344) (proposed 
rule). The MSO was listed as a threatened species effective April 15, 
1993 (58 FR 14248) (final rule). The primary reasons cited for 
conferring threatened status on the subspecies included the present or 
threatened destruction, modification, or curtailment of its habitat or 
range and the inadequacy of existing regulatory mechanisms. Secondary 
factors included the potential for catastrophic wildfire and potential 
competition and/or predation by other raptors, including the great 
horned owl (Bubo virginianus) and red-tailed hawk (Buteo jamaicensis).
    On August 16, 1993, the Service received a petition (delisting 
petition) from the Coalition of Arizona/New Mexico Counties for Stable 
Economic Growth (delisting petitioners) to remove the MSO from the List 
of Endangered and Threatened Wildlife (delist). Section 4(b)(3)(A) of 
the Act requires that the Service 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. To the maximum extent practicable, this 
finding is to be made within 90 days of receipt of the petition, and 
the finding is to be published promptly in the Federal Register.
    This finding is based on various documents, including the final 
rule, the delisting petition, and published and unpublished reports. 
All of these documents are on file in the Service's Southwest Regional 
Office and/or the New Mexico Ecological Services Field Office (see 
ADDRESSES section).
    The delisting petitioners presented 21 issues that they believed 
supported delisting the MSO; those issues, as presented in the 
petition, are addressed below. (The issues were numbered 1-20 in the 
delisting petition, but two issues received number 9. Those issues are 
addressed as 9a and 9b below.)
    Issue 1: The listing of the MSO has created ``de facto'' critical 
habitat throughout much of a five-state region.
    Response: ``Critical habitat'' consists of areas legally described 
and designated through a formal rulemaking process. The Service has not 
yet designated critical habitat for the MSO. The Service's listing and 
recovery actions, including section 7 consultation, have in no way 
implied the existence of MSO critical habitat.
    Issue 2: The Service believes that MSOs are exclusively associated 
with old-growth.
    Response: The Service has acknowledged that the owl uses a variety 
of habitat types, including old growth, but also second growth that 
provides complex habitat characteristics such as multiple canopy 
layers, moderate to high canopy closure, large trees, and abundant dead 
and downed woody material.
    Issue 3: No information in the administrative record for the 
listing of the MSO supports the theory that logging, increased 
predation, or lack of adequate regulation threatens the owl. In fact, 
the overly restrictive nature of MSO management precludes management of 
forests to reduce fuel loads and maintain healthy ecosystems.
    Response: There have been extensive surveys of capable habitat 
(i.e., habitat thought to be formerly suitable but, due to natural or 
anthropogenic causes, no longer considered suitable) adjacent to 
habitat identified as suitable. When owls are located at nest or roost 
sites, it is almost always in suitable habitat. There are records of 
owls foraging in recently harvested areas when these areas occur near 
suitable habitat. There have also been instances where owls have 
disappeared from areas following timber harvest (Larry Henson, Region 3 
Forest Service, in litt. 1993). The Service believes that there is 
adequate evidence that even-age management produces conditions that 
will not support owls over the long term.
    The Service has not maintained that owls cannot survive in forests 
that have experienced timber harvest. Much of the forest land in New 
Mexico and Arizona was extensively railroad-logged in the first decades 
of the twentieth century. Some of these areas, particularly in Lincoln 
National Forest, now support owls. Many railroad-logged areas in the 
Gila, Cibola, Santa Fe, Coconino, and Kaibab national forests, however, 
still do not support MSOs. It appears that in areas where productivity 
is high, suitable conditions can be restored in less than 100 years, 
even when the treatments were severe. Other areas, which have been 
selectively logged, have probably been continuously occupied by owls. 
The Service accepts that some harvest in second growth may hasten the 
return of suitable habitat conditions. The Service does not know the 
extent to which currently occupied habitat can be altered without 
adverse effects on the owl. The practice of even-age management called 
for in Region 3 Forest Management Plans has resulted in owls 
disappearing from previously occupied territories without subsequent 
return. The Forest Service is currently revising its Forest Management 
Plans; however, the revised guidelines have not yet been formally 
adopted.
    Service concern that forest fragmentation will increase predation 
by red-tailed hawks and great horned owls is based on the knowledge 
that these species prefer more open habitats. As the owl's habitat 
opens up under harvest, more great horned owls and red-tailed hawks are 
expected to occur closer to MSOs. The closer proximity may result in a 
higher rate of predation.
    The Service disagrees that management for the MSO will lead to 
increased fire risk and unhealthy forests. The Service has recognized 
the need for active management in order to reduce fuel loading in some 
areas where past fire suppression has created unnaturally dense stands 
and high fuel loads.
    Issue 4: The Service failed to appropriately solicit public and 
local government participation, which would have provided information 
to preclude listing, and failed to notify private individuals or 
organizations known to be affected by the proposed listing, counties in 
which the owl occurs, and the Republic of Mexico, of the proposal to 
list the subspecies. The delisting petitioners further claim that the 
public hearings to solicit public comment were inadequate.
    Response: The Service went well beyond all statutory requirements 
in soliciting and considering public comments prior to publication of 
the final rule. The Service opened a second comment period in addition 
to the initial 120-day comment period, although only a single 60-day 
comment period was required. The Service held 6 public hearings (3 in 
New Mexico, 2 in Arizona, and 1 in Utah) throughout the range of the 
owl, which were attended by approximately 883 people. Of those, 142 
people provided oral or written comments. Although no hearings were 
held in Colorado or Texas, hearings nearby in Alamogordo and Santa Fe, 
New Mexico; Cedar City, Utah; and Flagstaff, Arizona, were attended by 
individuals from neighboring states. People in Colorado and Texas also 
had ample opportunity to provide written testimony, which is considered 
equally with oral testimony. Furthermore, it is doubtful that 
substantive information from those two states that was not considered 
in the listing decision exists.
    Newspaper notices inviting public comment were published for each 
comment period as follows--20 notices in Arizona, 5 in New Mexico, 3 in 
Utah, and 2 in Colorado. In addition, more than 400 letters were sent 
to interested individuals, county governments, and relevant government 
agencies (including the Mexican Government, via the U.S. Embassy) 
following publication of the proposed rule. Comments were received from 
1,707 agencies, public officials, private organizations, companies, and 
individuals. The Service believes that the opportunities for public 
input were adequate.
    Issue 5: No formal communication was made to the Mexican 
Government; little or no information is available on the MSO in Mexico; 
and no scientifically conclusive statement can be made about its 
occurrence in that country. This is contrary to the requirement that 
the best scientific and commercial information be used in the listing 
process (section 4(b)(1)(A) of the Act and 50 CFR 424.14(b)).
    Response: The Service invited the Mexican Government to comment on 
the owl's status during the status review, in a letter transmitted by 
the U.S. Embassy in Laredo, Texas. The Mexican Government responded by 
letter expressing concern for the species in Mexico. The Service 
solicited comments on the proposed rule from the Mexican Government via 
the U.S. Embassy. The Mexican Government was similarly notified of 
publication of the final rule. The Service agrees that little 
information is available on the status of the owl in Mexico. 
Nevertheless, the Service believes that the best scientific and 
commercial information available was used in making a determination to 
list the MSO. Communications between the Service and Mexican officials 
have continued during the recovery planning process, and a Mexican 
representative has been appointed to the MSO Recovery Team.
    Issue 6: Only speculation was advanced in the proposed and final 
rules concerning owl populations in low- and middle-elevation riparian 
habitat. Organized owl surveys have not been conducted in riparian 
habitats; if they were conducted, many additional owls would be found.
    Response: The Service had to rely on historical accounts to find 
records of MSOs in low- and middle-elevation riparian habitats. As 
stated in the final rule, MSOs have been found in desert riparian 
systems in the past, but such habitats have been much reduced. Historic 
records also exist of owls breeding in desert riparian habitat. The 
Service speculates that these low-elevation riparian systems also may 
have served as dispersal corridors, although there are no hard data to 
support this. The Service also believes that there has been sufficient 
research in such systems in recent years to demonstrate that MSOs are 
no more than rarely found in desert riparian systems today. Where 
montane riparian habitats extend down canyons, they still provide 
important habitat for MSOs at lower elevations.
    Issue 7: There was no accounting for drought conditions during the 
period when owl surveys were conducted, and the drought caused a 
depression of apparent owl numbers because owls may not breed during 
drought conditions. The petitioners believed that this would limit 
responses during surveys.
    Response: The years 1991 and 1992 were wet years. Monitoring and 
demographic studies on Coconino and Gila national forests showed high 
reproductive output, as did monitoring on Lincoln National Forest 
during those years. During 1990, 18 monitored sites in New Mexico had 
very low reproduction. Reproduction during 1989, which was not a wet 
year, was similar to 1991-1992. The Service is not aware of any data 
that show conclusively that where territorial owls are present during 
the breeding season, they are less likely to be discovered during 
calling surveys when they are not breeding. The Service is aware of no 
data that would indicate that owls do not call during years when they 
do not breed.
    Issue 8: The Service miscalculated owl populations.
    Response: The Service used all available data on known owl 
occurrences in conjunction with information on the distribution of owl 
habitat acreage, surveyed habitat, and unsurveyed habitat to estimate 
the number of owls in the Southwest. The estimate included known owls, 
plus expected owls based on extrapolation of known owl densities over 
unsurveyed suitable habitat. The Service believes that the estimate 
provided in the final rule was reasonable, given the available data.
    Additional acres have been surveyed since the status review which 
produced the number published in the final rule. By the end of 1992, 
more than 1,500,000 acres of habitat had been surveyed in New Mexico 
and Arizona national forests. This is nearly half the habitat in New 
Mexico and Arizona. The following factors were considered in developing 
estimates of owl populations in Region 3 forests:
    1. The number of acres of suitable habitat in each national forest.
    2. The acres of suitable habitat surveyed in each forest.
    3. The number of management territories (a Forest Service term for 
MSO areas that fall under special management guidelines) designated in 
each forest.
    4. Formal monitoring data on occupancy rates in each forest.
    The procedure used in making the following estimates is the same 
one used in the status review, except that the analysis was done for 
each forest rather than dividing the range into north and south. 
Because more recent monitoring data have not yet been analyzed, the 
estimate is based on the occupancy rates through 1990, published in the 
status review. (Analysis of monitoring data from 1991 through 1993 is 
currently underway and will be used in the recovery planning process.) 
The calculations are presented in Table 1 by forest. In Table 1, the 
management territory number (MT#) equals the minimum number of 
management territories (Min) in the forest. The maximum number (Max) 
would be the number expected in all of the suitable habitat in the 
forest, if owls continue to be found at the present rate. The expected 
number (Exp) is an average of the minimum and the maximum. The expected 
number is based on the assumption (supported by Ward et al. 1991) that 
the rate of discovery will decline as surveys continue. Because there 
were differences in pair occupancy rates for northern New Mexico and 
southern New Mexico, based on formal monitoring, separate estimates 
were made for northern New Mexico and Arizona (40 percent pair 
occupancy), and southern Arizona and New Mexico (68 percent pair 
occupancy). The estimated number of pairs of owls (# Pairs) is given in 
Table 1 for each forest. The total number of single owls expected in 
Forest Service Region 3 is 495.91 and the total number of owls expected 
is 1,954.47.

   Table 1.--Calculation of the Number of Management Territories and Pairs of MSOs in Forest Service Region 3   
----------------------------------------------------------------------------------------------------------------
                                                         Suitable                                               
           National forest            Suitable acres     surveyed      MT# -Min     Max        Exp      # Pairs 
----------------------------------------------------------------------------------------------------------------
Apache/Sitgreaves...................         258,000         194,000         89        118        104      70.50
Carson..............................         250,000         148,000          3          5          4       1.61
Cibola..............................         172,000          63,000         29         79         54      36.78
Coconino............................         356,000         167,000        124        264        194     132.03
Coronado............................         107,000          78,000         97        133        115      78.22
Gila................................         619,000         225,000        147        404        276     187.48
Kaibab..............................          63,000          60,000          4          4          4       1.64
Lincoln.............................         371,000         267,000        114        158        136      92.62
Prescott............................         133,000          10,000         10        133         72      48.62
Santa Fe............................         476,000         110,000         32        138         85      34.09
Tonto...............................         317,000         182,000         49         85         67      45.68
                                     ---------------------------------------------------------------------------
      Total.........................       3,122,000       1,504,000        698      1,449      1,073     729.28
----------------------------------------------------------------------------------------------------------------

    There are no data available to justify changing the estimates of 
owl populations on non-Forest Service lands. The status review listed 
67 territories in northern New Mexico, 55 territories in southern New 
Mexico, and 249 territories in Arizona on non-Forest Service lands. If 
one assumes that occupancy rates on non-Forest Service lands are 
similar to those in national forests, an estimate of 624 birds on non-
Forest Service public and tribal lands in New Mexico and Arizona is 
derived (56 FR 56344). In 1992 there were an additional 64 birds known 
from Utah, 14 from Colorado, and 2 from Texas (58 FR 14248), for an 
estimated total of 2,658 on public and tribal lands in the Southwest 
U.S. Current estimates for the owl population on private lands in New 
Mexico and Arizona add another 41 birds for a total of 2,699 MSOs in 
the United States (see also Issue 15). It should be noted that this 
does not indicate that owl numbers have increased since 1990, but 
rather that more complete data provide a higher estimate.
    Issue 9a: Population estimates have been based on MSOs located 
during drought conditions, and locating methods were deficient.
    Response: The Service is required to base listing actions on the 
best scientific and commercial information available, and the data used 
at the time of listing constituted the best available data. The revised 
population estimate given in the response to Issue 8 is believed to be 
reasonable. (See discussion under Issues 7 and 8.)
    Issue 9b: Incorrect conclusions were drawn from Ganey and Balda 
(1989). Only select comments taken out of context were relied upon. 
This invalidates the positive listing petition finding.
    Response: Ganey and Balda's (1989) paper was not the only 
information used in the positive listing petition finding. The Service 
recognized the limitations of statements made in the paper and believes 
the information was correctly applied at all stages of the listing 
process. Although the comments mentioned in the delisting petition were 
not directly referenced in the Federal Register listing documents, the 
paper was considered in its entirety and reasonable conclusions were 
drawn.
    Issue 10: The Service has used the suitable and capable habitat 
designations to advance its argument for listing to the detriment of 
Southwest forest ecosystems. Forest Service figures (Fletcher 1990) for 
capable habitat are erroneous and were a poor basis on which to 
identify habitat threats.
    Response: The Service recognizes that identification of capable 
habitat can be difficult. However, the Forest Service is the agency 
best qualified to identify past management and its effects on habitat 
on its lands. Various sites in the ponderosa pine (Pinus ponderosa) 
type probably varied in quality as owl habitat prior to treatment, 
which caused them to be labeled ``capable'' by the Forest Service. Many 
of these sites were probably suitable owl habitat prior to treatment. 
More recent Forest Service estimates of suitable habitat (3,122,000 
acres) and capable habitat (1,040,000 acres) (Henson, in litt. 1993) 
are similar to the figures provided to the status review team (Fletcher 
1990). The figures for suitable habitat were derived by forest and 
district biologists from stand data bases, aerial photography, 
satellite data, and ground-truthing. Capable habitat was defined as 
habitat that had been suitable in the past, but because of natural or 
human-caused changes was no longer suitable.
    There is some confusion regarding the importance of ponderosa pine 
as an owl habitat type. Ponderosa pine appears to provide suitable 
habitat where it occurs in multiple canopy layers with high canopy 
closure and with abundant dead and downed woody material. These 
conditions now exist in some forests, and may have been more abundant 
prior to the extensive railroad-logging at the beginning of the 
century. The ponderosa pine forest type also appears to provide 
suitable habitat when it occurs on steep slopes adjacent to rock 
outcrops and in association with various species of hardwoods. It is 
often difficult to tell from the available data whether current second-
growth pine stands are capable of attaining suitability. The Service 
believes that the Forest Service acreage figures for suitable and 
capable habitat in Arizona and New Mexico represent the best scientific 
data available.
    Issue 11: The Service has not accurately described the nesting 
habits of the owl. The owl is an opportunist in regard to nest-site 
selection. As evidence for this, the petitioners note the owl's 
frequent use of old nests built by other species, which they claim 
shows adaptability and survival potential.
    Response: A lack of suitable nest structures was not discussed as a 
limiting factor to the MSO population in any listing document. As 
stated in the final rule, nesting habitat nearly always has a 
microclimate characterized as a cool, shady, humid site with 
substantial overhead cover. Thus, it is the loss of these microclimatic 
conditions, rather than nesting structures, that poses a risk to the 
MSO. Furthermore, it is unclear why the petitioners believe that use of 
other raptors' nests implies adaptability or survivability, because all 
owl species use existing structures for nesting rather than building 
their own.
    Issue 12: The decision to list the owl poses a threat to Southwest 
forest ecosystems. The petitioners state further that the forests are 
currently in a condition that is considerably more dense than in ``pre-
European'' times, and that this increased density creates fire and 
insect damage hazards and is detrimental to other species.
    Response: The Service agrees that many areas are overstocked with 
trees and may be at risk from fire, insects, and/or disease. That risk 
was recognized in the final rule. The Service does not agree that 
managing forests for a well-distributed population of owls will result 
in adverse conditions for other species. The Service has encouraged 
forest managers to adopt fire management plans and thinning of over-
stocked stands to reduce fire hazards and threats from insect pests.
    Issue 13: Data and studies from other owl subspecies should not be 
used to make listing determinations.
    Response: The Service disagrees. The Service is required to use the 
best scientific and commercial data to determine whether a species 
should be listed. The Service relied on studies of the conspecific 
northern (Strix occidentalis lucida) and California (S. o. 
occidentalis) spotted owls to supplement available information on the 
Mexican subspecies. The Service agrees that those data must be applied 
cautiously and that ecological differences in the habitats of the three 
subspecies must be taken into account.
    Issue 14: The term ``suitable habitat'' is not found in the Act, 
and the Service should only consider ``critical habitat'' in habitat 
discussions. The petitioners assert that, if the species is truly 
threatened, the final rule should have addressed critical habitat.
    Response: The term ``suitable habitat'' is appropriate when 
assessing the biological status of any species. In fact, any evaluation 
of a species' status would be incomplete without such a discussion, 
particularly where habitat loss is cited as a threat to the species. 
``Critical habitat'' is a legal term in the Act, and refers to areas 
officially designated through a rulemaking procedure. Therefore, the 
term ``suitable'' is appropriately used in the ``Summary of Factors 
Affecting the Species'' section of the final rule. In the ``Critical 
Habitat'' section of the final rule, the Service stated that, although 
much was known about the habitat requirements of the species, detailed 
maps necessary for determining critical habitat were not available at 
the time of listing, and therefore critical habitat was not 
determinable at that time. The Service has since initiated an effort to 
obtain the necessary additional information.
    Issue 15: Private land estimates in the final rule are inaccurate. 
Private lands are much more extensive than the Service claimed in the 
final rule. As evidence, the petitioners cite the Colfax Soil and 
Conservation District Long Range Plan (1981) as stating that privately 
owned commercial timber covers 656,818 acres in the district.
    Response: The Service figure of 5,000 acres, cited on page 38 of 
the status review, was based on known occupied habitat in Arizona and 
New Mexico. The delisting petitioners are correct in stating that the 
Service underestimated the extent of habitat on private land.
    The Service has calculated acres of suitable habitat on private 
land from Collins (1989), who provides acreage figures for non-Forest 
Service land in Arizona, and Van Hooser et al. (1993) who provide 
figures for ``private timberland'' in New Mexico. In New Mexico, 
2,000,000 acres attributed to private ownership includes Native 
American tribal lands. In New Mexico, tribal timberlands cover 641,278 
acres (Steve Haglund, Bureau of Indian Affairs (BIA) New Mexico Area 
Office, and James Carter, BIA Navajo Area Office, pers. comms. 1993). 
No owls have been confirmed in Carson National Forest in Taos County or 
Colfax County, despite extensive surveys. The acreage in Colfax County 
should therefore not be included as occupied habitat, even though 
suitable habitat may be present. This leaves 701,904 acres of private 
timberland in the remainder of New Mexico.
    More than 60 percent of New Mexico timberland (421,142 acres) is in 
the ponderosa pine type. Eleven percent of that (46,326 acres) is 
stocked at a rate greater than 5,000 board feet per acre (BFA), which 
is less than the stocking that is usually found in suitable owl 
habitat. Because there are no figures relating the acreage of suitable 
habitat on private land, the Service uses this stocking level as 
indicative of the acreage of suitable habitat in New Mexico. Spruce 
(Picea sp.), white fir (Abies concolor), Douglas-fir (Pseudotsuga 
menziesii), and aspen (Populus tremuloides) together occupy 16 percent 
of timberlands in New Mexico, and approximately two-thirds are stocked 
at greater than 5,000 BFA. This produces a figure of 67,383 acres in 
these forest types. Thus, in New Mexico there may be as much as 113,709 
acres of privately owned suitable timberland supporting spotted owls. 
This figure probably overestimates suitable owl habitat because it 
assumes that forests in private ownership have the same likelihood of 
suitability as forests in public or Native American ownership. This is 
unlikely, however, because private lands generally occur at lower 
elevations; thus they are drier and less productive. In addition, 
suitable owl habitat is likely to have a stocking level greater than 
5,000 BFA.
    Arizona has 1,317,076 acres of non-reserved timberland in non-
Forest Service ownership. In Arizona, Native American tribal lands 
occupy 1,260,162 acres (Conner et al. 1990). This leaves 56,914 acres 
of timberland in private ownership in Arizona. Approximately 84 percent 
(47,808 acres) is in ponderosa pine, and 14 percent (7,968 acres) is in 
Douglas-fir (Collins 1989). References for Arizona (Collins 1989, 
Conner et al. 1990) do not break down acreage by stocking level as was 
done in New Mexico. Rather, they provide productivity classes of 
greater or less than 50 cubic feet per acre per year. This figure may 
overestimate acreage in suitable habitat even more than stocking level, 
because it is based on site potential productivity values, rather than 
actual productivity. Thus, a stand that has been heavily harvested 
would be included even though low stocking might yield far lower growth 
(Garrett Blackwell, New Mexico State Forestry, pers. comm. 1993). 
Because this is the best figure available to estimate owl suitability, 
the Service is using it to identify potential suitable acreage on 
private lands in Arizona. Sixteen percent of non-Forest Service 
ponderosa pine timberland is capable of producing more than 50 cubic 
feet per acre (7,649 acres). The Service assumes that the proportion of 
mixed conifer that is suitable will be similar to that in New Mexico 
(67 percent), which yields an additional 5,259 acres of potential 
habitat on Arizona private lands. This yields a total of 12,908 acres 
of potential suitable owl habitat on private land in Arizona. Thus, a 
more accurate figure of between 125,000 and 130,000 acres of habitat 
probably exist on private lands in the two states.
    Assuming that the acreage is evenly divided between northern and 
southern New Mexico and Arizona, approximately 63,000 acres occur in 
the north and a similar acreage in the south. Owls in northern New 
Mexico and Arizona are found at the rate of one for each 15,092 acres 
surveyed. Thus approximately four owls would be expected on private 
land in the northern portions of the two states. In the south, owls are 
found at the rate of one for every 1,690 acres. This produces an 
estimated 37 birds. The Service does not believe that the addition of 
41 birds from private land is a sufficient increase to justify 
delisting.
    Issue 16: The total acreage of suitable habitat has been seriously 
underestimated by the Service and other agencies.
    Response: The Service has relied on suitable acreage figures 
provided by tribes and land-management agencies. The Service continues 
to believe that those agencies possess the best information available 
on the status of land under their administration or ownership. The 
Service critically examined Forest Service and other agency data during 
preparation of the status review, proposed rule, and final rule, and 
believes that these figures constitute the best available information. 
(See Response to Issue 8.)
    Issue 17: The evidence presented in the final rule is designed to 
protect ``old-growth'' forests, not MSOs. This is outside the intent of 
the Act, and the Service is ``administratively legislating'' both 
expansion of the Act and the missions of several land-management 
agencies.
    Response: In the final rule, the Service noted that owls use old 
growth where it is available within the species' range, but that they 
are not limited to old-growth forests. The final rule also pointed out 
that owls are frequently found in second-growth forests where those 
forests possess the attributes of suitable habitat (e.g., multiple 
canopy layers, moderate to high canopy closure). In addition, the final 
rule noted that owls are found in a variety of habitat types, from 
mixed conifer forests at high elevations to madrean oak and unforested 
slick-rock canyons at lower elevations. Further, any discussion of 
``old growth'' is related to how that habitat can support spotted owls. 
The Service's consideration of old growth and other habitats was 
essential in determining the status of the MSO.
    Issue 18: The final rule to list the owl did not provide the data 
necessary to support listing.
    Response: The Service disagrees. The decision was based upon the 
best scientific and commercial data available. The most important 
factors behind the decision to list were the present and threatened 
destruction of habitat, possible increases in predation resulting from 
habitat fragmentation, and the inadequacy of existing regulatory 
mechanisms.
    Issue 19: The Service failed to recognize statistical biases in the 
data regarding the owl, in that most surveys were motivated by timber 
sales.
    Response: The Service clearly addressed this bias in the status 
review, the proposed rule, and the final rule.
    Issue 20: The scientific and commercial information did not support 
a positive listing petition finding, nor, after the status review, a 
finding that listing was warranted.
    Response: The Service disagrees. The listing petition pointed out 
that forest plans called for additional conversion of owl habitat from 
suitable to capable, which, added to ongoing conversion, would result 
in the likely extinction of the subspecies. The protection offered by 
Forest Service Region 3 Interim Directive Number 2 (ID No. 2) was not 
considered to be adequate. The Service continues to believe, as do 
Forest Service researchers in the Northwest (Thomas et al. 1990) and 
California (Verner et al. 1992), that protection only of single 
territories, as proposed in ID No. 2, would inevitably lead to the 
extinction of habitat-dependent species. Based on continued and 
projected destruction of habitat and inadequate regulation, the Service 
determined that the MSO was likely to become an endangered species in 
the foreseeable future throughout all or a significant portion of its 
range.

Summary of Factors Affecting the Species

    Section 4(a)(1) of the Act and its implementing regulations (50 CFR 
part 424) set forth the procedures for adding species to or removing 
species from the Federal Lists. A species may be determined to be an 
endangered or threatened species due to one or more of the five factors 
described in section 4(a)(1). These factors and their application to 
the Mexican spotted owl, with reference to the delisting petition, are 
as follows:
    A. The present or threatened destruction, modification, or 
curtailment of its habitat or range. The delisting petitioners asserted 
that there is no threatened destruction, modification or curtailment of 
the owl's habitat or range. However, the final rule pointed out that, 
at the time of publication, Forest Management Plans still called for 
implementation of even-age management and steep slope harvest in owl 
habitat. Although harvest has slowed recently, individual projects have 
been modified to protect owl habitat, and the Forest Service is 
currently revising its Forest Management Plans, revised plans have not 
yet been formally adopted. Owl habitat reduction remains a concern of 
the Service.
    B. Overutilization for commercial, recreational, scientific or 
educational purposes. The delisting petitioners stated that there is no 
threat from overutilization of the species for commercial, 
recreational, or educational purposes. The Service agrees; this was the 
position held by the Service in the final rule.
    C. Disease or predation. The delisting petitioners stated that 
there is no threat from disease or predation. The Service remains 
concerned that opening the canopy in suitable owl habitat will increase 
contact with red-tailed hawks and great horned owls, species which 
occur in more open habitats. Increased contact may result in increased 
predation.
    D. The inadequacy of existing regulatory mechanisms. The delisting 
petitioners asserted that existing regulatory mechanisms provide 
adequate protection for owls. As discussed in Issue 20 above, the 
Service believes that the Forest Service's ID No. 2 would not provide 
adequate protection. The Service also notes that ID No. 2 has expired, 
and although it is still being implemented, there is no formal 
directive at this time to protect owl habitat in Forest Service Region 
3, where the majority of the population occurs.
    E. Other natural or manmade factors affecting its continued 
existence. The delisting petitioners asserted that no other natural or 
manmade factors threaten the owl. They further asserted that listing 
may jeopardize the owl because it will prevent the Forest Service from 
correctly managing forests to reduce threats from wildfire and insect 
and disease damage. The threat to owl habitat from wildfire has not 
changed since publication of the final rule. A change in Forest 
Management Plans that would decrease the threat from timber harvest has 
not yet been formalized. The Service disagrees with the delisting 
petitioners that listing itself brings new threats because of reducing 
the ability to manage for wildfire, insect, and disease threats. The 
Service encourages the Forest Service to address those threats with a 
variety of management options.
    In conclusion, the Service used the best scientific and commercial 
information available in all phases of the decision to list the Mexican 
spotted owl as a threatened species. The Service further believes that 
the factors for listing the species cited in the final rule have not 
changed substantially. Therefore, the Service finds that the delisting 
petitioners did not present substantial information indicating that 
delisting the MSO may be warranted. Through the recovery planning 
process, the Service is analyzing all available information in 
formulating a recovery plan for the MSO. The plan will contain 
objective, measurable criteria which, when met, could result in 
delisting the MSO.

References Cited

Collins, D.C. 1989. Timberland and woodland resources outside 
National Forests in Arizona, 1985. U.S.D.A. Forest Service Resource 
Bull. INT-66.
Conner, R.C., A.W. Green, J.D. Born, and R.A. O'Brien. 1990. Forest 
resources of Arizona. U.S.D.A. Forest Service Resource Bull. INT-69.
Fletcher, K.W. 1990. Habitats used, abundance and distribution of 
the Mexican spotted owl, Strix occidentalis lucida, on National 
Forest system lands. U.S.D.A. Forest Service, Southwestern Region, 
Albuquerque, New Mexico. 55 pp.
Ganey, J.L., and R.P. Balda. 1989. Distribution and habitat use of 
Mexican spotted owls in Arizona. Condor 91:355-361.
Thomas, J.W., E.D. Forsman, J.B. Lint, E.C. Meslow, B.R. Noon, and 
J. Verner. 1990. A conservation strategy for the northern spotted 
owl. Portland, Oregon. 458 pp.
Van Hooser, D.D., R.A. O'Brien, and D.C. Collins. 1993. New Mexico's 
forest resources. U.S.D.A. Forest Service Resource Bull. INT-79.
Verner, J., K.S. McKelvey, B.R. Noon, R.J. Gutierrez, G.I. Gould, 
Jr., and T.W. Beck. 1992. The California spotted owl: a technical 
assessment of its current status. U.S.D.A. Forest Service Tech. Rpt. 
PSW-GTR-133.
Ward, J.P., Jr., A.B. Franklin, and R.J. Gutierrez. 1991. Using 
search time and regression to estimate abundance of territorial 
spotted owls. Ecological Applications 1:207-214.

Author

    The primary authors of this notice are Dr. Buck Cully of the New 
Mexico Ecological Services Field Office, and Steve Spangle of the 
Southwest Regional Office (see ADDRESSES section).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531-1544).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, and Transportation.

    Dated: March 25, 1994.
Mollie H. Beattie,
Director, Fish and Wildlife Service.
[FR Doc. 94-7834 Filed 3-31-94; 8:45 am]
BILLING CODE 4310-55-P