[Federal Register: August 3, 2005 (Volume 70, Number 148)]
[Proposed Rules]               
[Page 44547-44552]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AU22; 1018-AI48

Endangered and Threatened Wildlife and Plants; Proposed Rule To 
Remove the Arizona Distinct Population Segment of the Cactus 
Ferruginous Pygmy-Owl From the Federal List of Endangered and 
Threatened Wildlife; Proposal To Withdraw the Proposed Rule To 
Designate Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.


SUMMARY: We, the U.S. Fish and Wildlife Service (Service), under the 
authority of the Endangered Species Act of 1973 (Act), as amended, 
propose to remove the Arizona distinct population segment (DPS) of the 
cactus ferruginous pygmy-owl (Glaucidium brasilianum cactorum) (pygmy-
owl) from the Federal List of Endangered and Threatened Wildlife and 
accordingly to eliminate its designated critical habitat. The Arizona 
DPS of the pygmy-owl was listed as endangered on March 10, 1997 (62 FR 
10730), and critical habitat was designated on July 12, 1999 (64 FR 
37419). On January 9, 2001, a coalition of plaintiffs filed a lawsuit 
with the District Court of Arizona challenging the validity of our 
listing of the pygmy-owl as a DPS and the designation of its critical 
habitat. After the District Court of Arizona remanded the designation 
of critical habitat (National Association of Home Builders et al. v. 
Norton, Civ.-00-0903-PHX-SRB), we proposed a new critical habitat 
designation on November 27, 2002 (67 FR 7102). Ultimately, as a result 
of this lawsuit, the United States Court of Appeals for the Ninth 
Circuit issued an opinion on August 19, 2003, stating that ``the FWS 
acted arbitrarily and capriciously in designating the Arizona pygmy-owl 
population as a DPS under the DPS Policy'' (National Association of 
Home Builders v. Norton, 340 F. 3d 835, 852 (9th Cir. 2003)). In light 
of the Ninth Circuit's opinion, we have reassessed the application of 
the DPS significance criteria to the Arizona pygmy-owl. Based on our 
assessment, we do not believe that the available information and 
science satisfy the criteria to indicate that pygmy-owls in Arizona are 
an entity that qualifies for listing under the Act. Accordingly, we 
propose to remove the Arizona population of pygmy-owls from the list in 
50 CFR 17.11, remove the critical habitat designation for this 
population at 50 CFR 17.95, and withdraw our November 27, 2002, 
proposed rule to designate new critical habitat.

DATES: We will accept comments until October 3, 2005. Public hearing 
requests must be received by September 19, 2005.

ADDRESSES: Comments and materials concerning the proposed delisting of 
the Arizona DPS of the pygmy-owl should be sent to the Field 
Supervisor, U.S. Fish and Wildlife Service, Arizona Ecological Services 
Field Office, 2321 West Royal Palm Road, Suite 103, Phoenix, Arizona 
85021-4951. Written comments may also be sent by facsimile to 602/242-
2513. Comments and materials received will be available for public 
inspection, by appointment, during normal business hours at the above 

FOR FURTHER INFORMATION CONTACT: Steve Spangle, Field Supervisor (see 
ADDRESSES) (telephone 602/242-0210; facsimile 602/242-2513).


Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be based on the best available information. We have gathered and 
evaluated new information related to the pygmy-owl that has become 
available since the 1997 listing and are seeking any other pygmy-owl 
information. We will continue to support surveys of pygmy-owls in 
Mexico to further elucidate the status of the species in Mexico, and to 
identify threats to the population.
    We are soliciting comments or suggestions from the public, other 
concerned governmental agencies, the scientific community, industry, or 
any other interested party concerning this proposed rule. We are 
particularly interested in comments concerning:
    (1) Biological, genetic, and/or morphological data related to the 
taxonomic classification of the pygmy-owl throughout its current range;
    (2) The location and characteristics of any additional populations 
not considered in previous work that might have bearing on the current 
population status;
    (3) Additional information related to current versus historical 
range, current distribution, genetic diversity, and population sizes of 
the Arizona pygmy-owl population and its contribution to the taxon as a 
    (4) Status of the pygmy-owl in Mexico, particularly threats to 
populations or habitat; and
    (5) Information related to discreteness, significance, and 
conservation status of any potential pygmy-owl DPS.
    We will take into consideration the comments and any additional 
information received, and such communications may lead to a final 
determination that differs from this proposal.


    The cactus ferruginous pygmy-owl (Glaucidium brasilianum cactorum) 
(pygmy-owl) is in the order Strigiformes and the family Strigidae. It 
is a small bird, approximately 17 centimeters (cm) (6.75 inches (in)) 
long. Males average 62 grams (g) (2.2 ounces (oz)), and females average 
75 g (2.6 oz). The pygmy-owl is reddish brown overall, with a cream-
colored belly streaked with reddish brown. Color may vary, with some 
individuals being more grayish brown. The crown is lightly streaked, 
and a pair of black/dark brown spots outlined in white occur on the 
nape suggesting ``eyes.'' This species lacks ear tufts, and the eyes 
are yellow. The tail is relatively long for an owl and is colored 
reddish brown with darker brown bars (Proudfoot and Johnson 2000). The 
pygmy-owl is primarily diurnal (active during daylight) with 
crepuscular (active at dawn and dusk) tendencies. They can be heard 
making a long, monotonous series of short, repetitive notes, mostly 
during the breeding season (Proudfoot and Johnson 2000).
    The pygmy-owl is one of four subspecies of the ferruginous pygmy-
owl. It occurs from lowland central Arizona south through western 
Mexico to the States of Colima and Michoacan, and from southern Texas 
south through the Mexican States of Tamaulipas and Nuevo Leon. Only the 
Arizona population of the pygmy-owl is listed as an endangered species 
(62 FR 10730; March 10, 1997).
    Historically, pygmy-owls were recorded in association with riparian 
woodlands in central and southern Arizona (Bendire 1892; Gilman 1909; 
Johnson et al. 1987). Plants present in these riparian communities 
included cottonwood (Populus fremontii), willow (Salix spp.), ash 
(Fraxinus velutina), and hackberry (Celtis spp.). However, recent 
records have documented that pygmy-

[[Page 44548]]

owls are found in a variety of vegetation communities such as riparian 
woodlands, mesquite (Prosopis velutina and P. glandulosa) bosques 
(Spanish for woodlands), Sonoran desertscrub, semidesert grassland, and 
Sonoran savanna grassland communities (Monson and Phillips 1981; 
Johnson and Haight 1985; Proudfoot and Johnson 2000) (see Brown 1994 
for a description of these vegetation communities). While native and 
nonnative plant species composition differs among these communities, 
there are certain unifying characteristics such as (1) the presence of 
vegetation in fairly dense thickets or woodlands, (2) the presence of 
trees, saguaros (Carnegiea giganteus), or organ pipe cactus 
(Stenocereus thurberi) large enough to support cavities for nesting, 
and (3) elevations below 1,200 meters (m) (4,000 feet (ft)) (Swarth 
1914; Karalus and Eckert 1974; Monson and Phillips 1981; Johnsgard 
1988; Enriquez-Rocha et al. 1993; Proudfoot and Johnson 2000). Large 
trees provide canopy cover and cavities used for nesting, while the 
density of mid- and lower-story vegetation provides foraging habitat 
and protection from predators and contributes to the occurrence of prey 
items (Wilcox et al. 2000).

Previous Federal Action

    On May 26, 1992, a coalition of environmental organizations (Galvin 
et al. 1992) petitioned us to list the entire cactus ferruginous pygmy-
owl subspecies as endangered under the Act. We published a finding that 
the petition presented substantial scientific or commercial information 
indicating that listing of the pygmy-owl may be warranted and commenced 
a status review of the subspecies (58 FR 13045; March 9, 1993). As a 
result of information collected and evaluated during the status review, 
including information collected during a public comment period, we 
proposed to list the pygmy-owl as endangered with critical habitat in 
Arizona and threatened in Texas (59 FR 63975; December 12, 1994). After 
a review of all comments received in response to the proposed rule, we 
published a final rule listing the pygmy-owl as endangered in Arizona 
(62 FR 10730; March 10, 1997). In that final rule, we determined that 
listing in Texas was not warranted and that critical habitat 
designation for the Arizona population was not prudent.
    On October 31, 1997, the Southwest Center for Biological Diversity 
filed a lawsuit in Federal District Court in Arizona against the 
Secretary of the Department of the Interior for failure to designate 
critical habitat for the pygmy-owl and a plant, Lilaeopsis 
schaffneriana var. recurva (Huachuca water umbel) (Southwest Center for 
Biological Diversity v. Babbitt, CIV 97-704 TUC ACM). On October 7, 
1998, the District Court issued an order that, along with subsequent 
clarification from the Court, required proposal of critical habitat by 
December 25, 1998, followed by a final determination 6 months later.
    In September 1998, we appointed the Cactus Ferruginous Pygmy-owl 
Recovery Team (Recovery Team), comprised of biologists (pygmy-owl 
experts and raptor ecologists) and representatives from affected and 
interested parties (i.e., Federal and State agencies, local 
governments, the Tohono O'odham Nation, and private groups). On January 
9, 2003, we published a notice of availability in the Federal Register 
(68 FR 1189) opening the public comment period for the draft pygmy-owl 
recovery plan until April 9, 2003. On April 30, 2003 (68 FR 23158), we 
reopened the public comment period on the recovery plan until June 30, 
    On December 30, 1998, we proposed to designate critical habitat in 
Arizona for the pygmy-owl (63 FR 71820). On April 15, 1999, we released 
the draft economic analysis on proposed critical habitat and reopened 
the public comment period for 30 days (64 FR 18596). On July 12, 1999, 
we published our final critical habitat determination (64 FR 37419), 
essentially designating the same areas as were proposed.
    On January 9, 2001, a coalition of plaintiffs filed a lawsuit with 
the District Court of Arizona challenging the validity of the Service's 
listing of the Arizona population of the pygmy-owl as an endangered 
species and the designation of its critical habitat. On September 21, 
2001, the Court upheld the listing of the pygmy-owl in Arizona but, at 
our request, and without otherwise ruling on the critical habitat 
issues, remanded the designation of critical habitat for preparation of 
a new analysis of the economic and other effects of the designation 
(National Association of Home Builders et al. v. Norton, Civ.-00-0903-
PHX-SRB). The Court also vacated the critical habitat designation 
during the remand. Subsequently, the Court ordered that we submit the 
critical habitat proposed rule to the Federal Register on or before 
November 15, 2002. On November 27, 2002, we published the proposed rule 
to designate critical habitat for the pygmy-owl (67 FR 7102) and opened 
a public comment period on the proposed rule and the draft economic 
analysis until February 25, 2003. We extended the comment period on 
February 25, 2003, until April 25, 2003 (68 FR 8730). We then reopened 
the comment period on April 28, 2003, until June 27, 2003 (68 FR 
22353). Due to a lack of funding, work on the final rule designating 
critical habitat for the pygmy-owl was suspended in April 2003.
    The plaintiffs appealed the District Court's ruling on the listing 
of the pygmy-owl as a distinct population segment. On August 19, 2003, 
the Ninth Circuit Court of Appeals upheld the Service's determination 
that the Arizona pygmy-owl population was discrete, but found that the 
Service did not articulate a rational basis for finding that the 
Arizona pygmy-owl population was significant to the taxon, as discussed 
in further detail below (National Association of Home Builders v. 
Norton, 340 F. 3d. at 852). The judgment of the District Court was 
reversed, and the case was remanded to the District Court for further 
proceedings consistent with the Ninth Circuit's opinion.
    The Ninth Circuit's opinion and the Service's lack of funding to 
complete work on the final critical habitat designation prompted us to 
file a declaration with the District Court of Arizona requesting to 
stay or modify the Court-ordered critical habitat completion deadline 
of September 29, 2003. On September 29, 2003, the Court granted a stay 
pending further order of the Court.
    On October 1, 2003, the interveners-appellees petitioned for a 
rehearing from the Ninth Circuit. That request was denied. On November 
12, 2003, the plaintiffs filed a motion with the District Court seeking 
removal of the listing based on the Ninth Circuit's ruling. On December 
10, 2003, the Service filed a response agreeing that removal of the 
listing was appropriate. The motion also indicated that the Service was 
undertaking an internal review of the current status of the pygmy-owl 
in the United States and Mexico and was engaged in ongoing surveys of 
the species. The interveners in the case opposed the plaintiffs' motion 
and disputed the contention that the listing rule should be removed.
    On June 25, 2004, the District Court for the District of Arizona 
(CV 00-0903 PHX-SRB) remanded the listing rule to the Service for 
reconsideration consistent with the Ninth Circuit's ruling and ordered 
that the pygmy-owl listing should remain in place for the duration of 
the Service's deliberations. On January 31, 2005, pursuant to the 
District Court's order, we filed a status report with the District 
Court regarding our reconsideration of the listing rule for the pygmy-
owl. This proposed rule to delist the Arizona DPS of the pygmy-owl is 
the result of our evaluation of

[[Page 44549]]

whether the DPS is a listable entity under the Act.

Distinct Vertebrate Population Segment

    We must consider a species for listing under the Act if available 
information indicates that such an action might be warranted. 
``Species'' is defined by the Act as including any species or 
subspecies of fish and wildlife or plants, and any distinct vertebrate 
population segment of fish or wildlife that interbreeds when mature (16 
U.S.C. 1532(16)). We, along with the National Marine Fisheries Service 
(National Oceanic and Atmospheric Administration--Fisheries), developed 
the Policy Regarding the Recognition of Distinct Vertebrate Population 
Segments (DPS Policy) (61 FR 4722) to help us in determining what 
constitutes a DPS. Under this policy, we use three criteria to assess 
whether a population under consideration for listing may be recognized 
as a DPS: (1) Discreteness of the population in relation to the 
remainder of the species to which it belongs; (2) the significance of 
the population segment to the species to which it belongs; and (3) the 
population segment's conservation status in relation to the Act's 
standards for listing.
    A population segment may be considered discrete if it satisfies 
either one of the following conditions: (1) Marked separation from 
other populations of the same taxon (a group of organisms that form a 
unit of classification, e.g., a family, genus, species, subspecies) 
resulting from physical, physiological, ecological, or behavioral 
factors, including genetic discontinuity; or (2) populations delimited 
by international boundaries within which differences in control of 
exploitation, management of habitat, conservation status, or regulatory 
mechanisms exist that are significant in light of 4(a)(1)(D) of the 
    If a population is considered discrete under one or more of the 
above conditions, its biological and ecological significance is 
assessed. Measures of significance may include, but are not limited to, 
the following: (1) Persistence of the discrete population segment in an 
ecological setting unusual or unique for the taxon; (2) evidence that 
loss of the discrete population segment would result in a significant 
gap in the range of the taxon; (3) evidence that the discrete 
population segment represents the only surviving natural occurrence of 
the taxon that may be more abundant elsewhere as an introduced 
population outside its historical range; and (4) evidence the discrete 
population segment differs markedly from other populations of the taxon 
in its genetic characteristics.
    If a population segment is discrete and significant, its evaluation 
for endangered or threatened status will be based on the Act's 
definitions of those terms and a review of the factors enumerated in 
section 4(a). Endangered means the species is in danger of extinction 
throughout all or a significant portion of its range. Threatened means 
the species is likely to become endangered within the foreseeable 
future throughout all or a significant portion of its range.

Delisting Analysis: Proposed Application of the Significance Criteria 
to the Pygmy-Owl in Arizona

    In the discussion below we provide our preliminary analysis of the 
significance of the Arizona DPS in light of our DPS policy and the 
Ninth Circuit's ruling in this case. In doing so we considered 
information known at the time of the listing of the pygmy-owl, as well 
as information obtained subsequently. This is consistent with the June 
25, 2004, ruling by the District Court remanding the rule back to the 
Service for reconsideration, which held that once a rule has been 
declared arbitrary and capricious and it is remanded to the agency for 
further consideration, the agency may use all information available at 
the time of reconsideration. Prior to making a final determination we 
will consider any new information obtained during the public comment 
period and make any necessary revisions.
    (1) Persistence of the discrete population segment in an ecological 
setting unusual or unique for the taxon.
    Approximately three quarters of the distribution of the pygmy-owl 
occurs within tropical and subtropical plant communities. This includes 
pygmy-owls of southern Texas south through the Mexican States of 
Tamaulipas and Nuevo Leon, which occupy mesquite forest, riparian 
forest, thorn forest, tropical deciduous forest, heavy riparian forest, 
and areas more tropical in nature, including cypress groves (Cartron et 
al. 2000b; Proudfoot and Johnson 2000; Leopold 1950). It also includes 
areas in southern Sonora, Sinaloa, and Nayarit where pygmy-owls occur 
within the tropical Sinaloan thornscrub and Sinaloan deciduous forest 
community types and associated riparian communities (Leopold 1950; 
Brown 1994; Phillips and Comus 2000).
    Approximately one quarter of the distribution of pygmy-owls falls 
within desert plant communities. This includes pygmy-owls in Arizona 
south through western Mexico into the State of Sonora. In Arizona, the 
pygmy-owl is found within Sonoran Desert scrub or semidesert grassland 
biotic communities and associated riparian and xeroriparian (dry 
washes) communities (Cartron et al. 2000b; Proudfoot and Johnson 2000). 
In northern Sonora, Mexico, the ecological setting in which the pygmy-
owl is found exhibits similar ecological conditions to the range of the 
Arizona pygmy-owl with regard to vegetation, climate, soils, etc. 
(Leopold 1950; Brown 1994; Phillips and Comus 2000; http://mexico 

    In northern Sonora, Mexico, millions of acres of Sonoran Desert and 
thornscrub are being converted to buffelgrass (Pennisetum ciliaris). 
This direct loss of habitat from the conversion to buffelgrass also 
results in an indirect loss of habitat because of invasion of 
buffelgrass into adjacent areas and increased fire frequency and 
intensity in buffelgrass savannas (Burquez-Montijo et al. 2002). Little 
is known about the direct effects of fire on pygmy-owl behavior or 
distribution. We have no research information at our disposal that 
follows the behavior of and impacts to owls before, during and 
following natural fire events. Flesch (2003) concluded that the 
conversion of native vegetation to buffelgrass savannas constitutes a 
serious threat to pygmy-owls by eliminating or suppressing regeneration 
of large columnar cacti in northern and central Sonora, especially in 
areas where saguaros are already uncommon (Flesch 2003). Buffelgrass 
areas have significantly lower species diversity and reduced structural 
complexity than the native desert scrub (Van Devender and Dimmit 2000). 
Pygmy-owls were found in or adjacent to buffelgrass clearings that 
formed a mosaic of artificial savannah and native vegetation (Flesch 
2003). The conversion of native vegetation to buffelgrass and the 
associated direct and indirect effects on habitat are an ongoing threat 
to pygmy-owls in Mexico (Flesch 2003). Survey data indicate that pygmy-
owls are patchily distributed in Sonora, Mexico (Flesch 2003). This 
conversion of native vegetation to buffelgrass may be serving to create 
an ecological setting that is very different than that occupied by 
Arizona pygmy-owls.
    Johnson et al. (2003) examined previous population and site 
locations for owls between 1872 and 1971. They found that, 
historically, the owl used riparian zones along streams and later 
transitioned to the more xeric habitat of cacti. They believed a direct 
correlation exists between the timeframe of the 1920s, when numerous 
water projects

[[Page 44550]]

were constructed resulting in reduced stream flows, and a downward 
trend in population numbers as compared to 1880-1920. Thus, their work 
argues against a clear indication that more current events resulted in 
population reductions, or that there has been a precipitous decline 
since the changes that occurred just after the turn of the century.
    (2) Evidence that loss of the discrete population segment would 
result in a significant gap in the range of the taxon.
    In the listing rule (March 10, 1997; 62 FR 10730), we found that 
the gap in the range of the taxon through loss of the Arizona pygmy-
owls would be significant because it would: (a) Decrease the genetic 
variability of the taxon; (b) reduce the current range of the taxon; 
(c) reduce the historical range of the taxon; and (d) extirpate the 
western pygmy-owls from the United States.
    With regard to genetic variability, factor (a) above, in our 
listing rule we were able to determine genetic distinctness between 
western and eastern pygmy-owls; however, we did not have evidence of 
genetic differences between pygmy-owls in Arizona and northwestern 
Mexico. Proudfoot and Slack (2001) present the most current and 
extensive work on the genetics of the pygmy-owl. They found that there 
were distinct differences between pygmy-owls in Arizona and Texas. 
Their work also showed genetic differences between pygmy-owls in 
eastern and western Mexico. However, we have no evidence of a marked 
genetic difference between the Arizona pygmy-owls and those in the rest 
of the western range. Glenn Proudfoot, Texas A&M University, will 
shortly complete some additional pygmy-owl genetic analysis using a 
different methodology (S. Richardson, pers. comm., 2005). These 
analyses are expected to be available very soon and may be relevant to 
our final decision. We will review this information when it becomes 
    Given the genetic and geographic separation between the eastern and 
western pygmy-owls and the habitat differences within the western 
population of desert and subtropical/tropical plant communities, 
Arizona pygmy-owls at the northern periphery of the western range 
represent a potential source of genetic diversity within the range of 
the taxon. Recent pygmy-owl genetic work, done by Proudfoot at Texas 
A&M, presents evidence that genetic divergence occurs in both Arizona 
and Sonora, Mexico. A distinct genetic clade exists in northwest Tucson 
and genetic separation exists between Sonora and Sinaloa indicating 
that separate groups of pygmy-owls, including Arizona, contribute to 
the overall genetic diversity of this subspecies (Proudfoot and Slack 
2001, Proudfoot 2005). Genetic divergence tends to occur at the 
periphery of a species' range (Lesica and Allendorf 1995). The 
peripheral nature of the Arizona pygmy-owls may increase the potential 
for the population to diverge from populations in Sonora and Sinaloa, 
Mexico. Because peripheral populations may be isolated to some extent 
from core populations, peripheral populations may become genetically 
distinct because of genetic drift (random gene frequency changes in a 
small population due to chance alone) and divergent natural selection 
(the natural process by which organisms leave differentially more or 
fewer descendants than other individuals because they possess certain 
inherited advantages or disadvantages) (Lesica and Allendorf 1995). 
However, we have no evidence to suggest a marked genetic difference 
between the Arizona pygmy-owls and the rest of the western pygmy-owls.
    With regard to factor (b), a reduction in current range, the Ninth 
Circuit looked to other DPS rules and findings published by the 
Service. The Court stated that the Service had previously found two 
ways in which the loss of a discrete population could reduce the 
current range of its taxon. First, the Court concluded that a gap could 
be significant if the loss of the population would amount to a 
``substantial reduction'' of the taxon's range. The Court noted the 
final listing rule for the pygmy-owl stated that the Arizona population 
represented only a small percentage of the total current range of 
western pygmy-owls, and the Service did not find that the loss of this 
``small percentage'' would substantially curtail the current range. 
Second, ``the loss of a discrete population that is numerous and 
constitutes a large percentage of the total number of taxon members 
could be considered a significant curtailment of a taxon's current 
range'' (340 F.3d. at 845). The Court noted the Service did not find 
that the ``20 to 40 individuals [in the Arizona population] would 
significantly curtail the western pygmy-owls' current range, which 
consists mostly of the more-numerous northwestern Mexico pygmy-owl 
population'' (340 F.3d. at 845). In this case, the range of the taxon 
(Glaucidium brasilianum cactorum), includes both the western pygmy-owl 
population occurring from lowland central Arizona south through western 
Mexico to the States of Colima and Michoacan, and the eastern pygmy-owl 
population from southern Texas south through the Mexican States of 
Tamaulipas and Nuevo Leon. Taking into account our DPS policy, as well 
as the analysis of the Ninth Circuit, we conclude that the loss of the 
Arizona population would not result in a significant gap in the range 
of the taxon due to a reduction in the current range of the subspecies. 
Because this Arizona population occupies only a small percentage of the 
range of the subspecies, its loss would not amount to a substantial 
reduction of the range of the subspecies.
    With regard to factor (c) above, we found in our original listing 
rule that the gap would be significant because the loss of the Arizona 
pygmy-owls would reduce the historical range of the taxon. We 
determined this because the Arizona population is at the periphery of 
the western pygmy-owl's historical range, and that this peripheral 
population was always a stable portion of that range. The Ninth Circuit 
found that alone does not make Arizona a major geographical area in the 
western pygmy-owl's historic range. The Ninth Circuit found that, while 
Arizona pygmy-owls might possibly be significant to its taxon's 
historic range, the Service did not articulate a reasoned basis in the 
listing rule as to why that is so. The historic ranges of the Arizona 
population and of the whole subspecies are not precisely known. Based 
upon the best information available, the historic range in Arizona was 
considerably larger than the population's current range in Arizona. 
However, even the historic range in Arizona was only a small percentage 
of the historic range of the entire subspecies. We have no other 
information suggesting that the historic range of the Arizona 
population represents ``a major geographical area'' such that, given 
the ruling of the Ninth Circuit, the loss of the Arizona population 
would result in a significant gap in the range of the taxon.
    We do believe that protection and management of some peripheral 
populations may be important to the survival and evolution of certain 
species. Population members most distant from the species' core 
regularly demonstrate adaptations not often seen in core populations. 
This in and of itself, however, does not satisfy the question of 
significance. Maintaining genetic diversity within the western 
population and the taxon as a whole may be important in the face of 
land use changes, primarily impacts from a conversion of native 
vegetation to agricultural crops and buffelgrass pastures for livestock 
grazing in Mexico (Burquez and Yrizar 1997). Land use

[[Page 44551]]

changes in Mexico may cause the reduction of the core pygmy-owl 
population in Mexico, and as such there might be an increased reliance 
on peripheral populations to maintain genetic adaptation and diversity. 
Peripheral populations often persist when core populations are 
extirpated (Channell and Lomolino 2000a, 2000b; Lomolino and Channell 
1995). In the face of changing environmental conditions, what 
constitutes a peripheral population today could be the center of the 
species' range in the future (Nielsen et al. 2001). Peripheral 
populations survive more frequently than do core populations when 
species undergo dramatic reductions in their range (greater than 75 
percent) (Channell and Lomolino 2000a). However, we do not have 
sufficient information to assess the likelihood of the Arizona 
peripheral population contributing to the long-term survival of the 
species. Additionally, as noted above, we do not have evidence to 
support a marked genetic difference between Arizona pygmy-owls and 
pygmy-owls in western Mexico.
    With regard to (d) above, we determined that a gap would be 
significant because it would deprive the United States of its portion 
of the western pygmy-owl's range. The Ninth Circuit Court rejected this 
argument as a misconstruction of this criterion. The Court found that 
in designating a DPS under the DPS policy, we must find that a discrete 
population is significant to the taxon as a whole, not to the United 
States. Therefore, we have determined, based on the information 
available to the Service, that loss of the Arizona population would not 
result in a significant gap in the range of the subspecies on the basis 
of the significance of the Arizona population to the subspecies' status 
as a whole.
    (3) Evidence that the discrete population segment represents the 
only surviving natural occurrence of the taxon that may be more 
abundant elsewhere as an introduced population outside its historical 
    This criterion does not apply to the Arizona population of the 
    (4) Evidence the discrete population segment differs markedly from 
other populations of the taxon in its genetic characteristics.
    As discussed above, we do not have evidence to support that there 
is a marked genetic difference between pygmy-owls in Arizona and the 
rest of the western population of pygmy-owls.
    On the basis of the discussion above, we believe that the Arizona 
population of the pygmy-owl does not meet the definition of a DPS in 
accordance with our 1996 DPS policy. As such, we are proposing to 
remove the Arizona DPS of the cactus ferruginous pygmy-owl from the 
Federal List of Endangered and Threatened Wildlife on the basis that 
the original classification data was in error. Accordingly, we are also 
proposing to remove the designation of critical habitat at 50 CFR 
17.95(b) for the Arizona DPS of the pygmy-owl, and we are proposing to 
withdraw our proposed rule of November 27, 2002 (67 FR 71032) to set 
forth new critical habitat for this population.

Effects of the Proposed Rule

    If the Arizona DPS of the pygmy-owl is delisted, the requirements 
under section 7 of the Act would no longer apply. Federal agencies 
would be relieved of the need to consult with us on their actions that 
may affect the pygmy-owl and to insure that any action they authorize, 
fund, or carry out is not likely to jeopardize the continued existence 
of the pygmy-owl. Federal agencies would also be relieved of their 
responsibilities under section 7(a)(1) of the Act to use their 
authorities to further the conservation of the pygmy-owl. Additionally, 
we would not finalize the designation of critical habitat proposed on 
November 2, 2002 (67 FR 71032) nor would we complete a final recovery 
    Permitted scientific take as a result of surveys and research would 
likely continue to be regulated by the State of Arizona, Arizona Game 
and Fish Department, and will be considered in the context of potential 
effects to population stability.

Peer Review

    In accordance with our policy published on July 1, 1994 (59 FR 
34270), we will solicit the expert opinions of at least three 
appropriate and independent specialists regarding this proposed rule. 
The purpose of such review is to ensure that our proposal is based on 
scientifically sound data, assumptions, and analyses. We will send 
these peer reviewers copies of this proposed rule immediately following 
publication in the Federal Register. We will invite these peer 
reviewers to comment, during the public comment period, on the specific 
assumptions and conclusions regarding this proposal. We will consider 
all comments and information received during the 60-day comment period 
on this proposed rule as we prepare our final rulemaking.

Public Hearings

    Section 4(b)(5)(E) of the Act provides for one or more public 
hearings on this proposal, if requested. Requests must be received 
within 45 days of the date of publication of the proposal in the 
Federal Register. Such requests must be made in writing and be 
addressed to the Field Supervisor (see ADDRESSES section). We will 
schedule public hearings on this proposal, if any are requested, and 
announce the dates, times, and places of those hearings in the Federal 
Register and local newspapers at least 15 days prior to the first 

Clarity of the Rule

    Executive Order 12866 requires each Federal agency to write 
regulations that are easy to understand. We invite your comments on how 
to make this proposal easier to understand including answers to 
questions such as the following: (1) Is the discussion in the 
SUPPLEMENTARY INFORMATION section of the preamble helpful in 
understanding the proposal? (2) Does the proposal contain technical 
language or jargon that interferes with its clarity? (3) Does the 
format of the proposal (grouping and order of sections, use of 
headings, paragraphing, etc.) aid or reduce clarity? What else could we 
do to make the proposal easier to understand?
    Send a copy of comments that concern how we could make this 
proposal easier to understand to Office of Regulatory Affairs, 
Department of the Interior, Room 7229, 1849 C Street, NW., Washington, 
DC 20240. You may also send comments by e-mail to Exsec@ios.doi.gov.

Required Determinations

Paperwork Reduction Act

    OMB regulations at 5 CFR 1320, which implement provisions of the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.), require that 
Federal agencies obtain approval from OMB before collecting information 
from the public. Implementation of this proposal does not include any 
collections of information that require approval by OMB under the 
Paperwork Reduction Act.

National Environmental Policy Act (NEPA)

    We have determined that Environmental Assessments and Environmental 
Impact Statements, as defined under the authority of the National 
Environmental Policy Act of 1969, need not be prepared in connection 
with regulations adopted pursuant to section 4(a) of the Endangered 
Species Act of 1973, as amended. A notice outlining our reasons for 
this determination was published in the Federal Register on October 25, 
1983 (48 FR 49244).

[[Page 44552]]

References Cited

    A complete list of all references cited in this proposed rule is 
available upon request from the Arizona Ecological Services Field 
Office (see ADDRESSES section).

List of Subjects in 50 CFR Part 17

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

Proposed Regulation Promulgation

    Accordingly, we hereby propose to amend part 17, subchapter B of 
Chapter I, title 50 of the Code of Federal Regulations, as set forth 


    1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

Sec.  17.11  [Amended]

    2. Amend Sec.  17.11(h) by removing the entry for ``Pygmy-owl, 
cactus ferruginous'' under BIRDS from the List of Endangered and 
Threatened Wildlife.

Sec.  17.95  [Amended]

    3. Amend Sec.  17.95(b) by removing the entry for ``Cactus 
Ferruginous Pygmy-owl (Glaucidium brasilianum cactorum).''

    Dated: July 27, 2005.
Marshall P. Jones, Jr.,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 05-15302 Filed 8-2-05; 8:45 am]