[Federal Register Volume 59, Number 237 (Monday, December 12, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30468]


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[Federal Register: December 12, 1994]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AC85

 

Endangered and Threatened Wildlife and Plants; Proposed Rule to 
List the Cactus Ferruginous Pygmy-Owl as Endangered With Critical 
Habitat in Arizona and Threatened in Texas

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The Fish and Wildlife Service (Service) announces a 12-month 
finding on a petition to list the cactus ferruginous pygmy-owl 
(Glaucidium brasilianum cactorum) as endangered under the authority of 
the Endangered Species Act of 1973, as amended (Act). The Service finds 
that the petitioned action is warranted and proposes to list the cactus 
ferruginous pygmy-owl as endangered in Arizona, and as threatened in 
Texas. Listing is not warranted at this time in its range in Mexico. 
The former breeding range of this bird extended from south-central 
Arizona south through western Mexico, and from southern Texas south 
through northeastern Mexico. Within these regions, the species occurs 
in riverbottom woodlands, coastal plain oak associations, thornscrub, 
and desertscrub associations.The cactus ferruginous pygmy-owl is 
threatened to varying degrees across its range by loss and modification 
of habitat, lack of adequate protective regulations, and other factors. 
This proposal, if made final, would implement Federal protection 
provided by the Act for the cactus ferruginous pygmy-owl in the United 
States. Critical habitat is being proposed in Arizona.

DATES: Comments from all interested parties must be received by April 
11, 1995: Public hearing requests must be received by February 27, 
1995.

ADDRESSES: Comments and materials concerning this proposal should be 
sent to the State Supervisor, Arizona Ecological Services State Office, 
Fish and Wildlife Service, 3616 West Thomas Road, Suite 6, Phoenix, 
Arizona 85019. Comments and materials received will be available for 
public inspection, by appointment, during normal business hours at the 
above address.

FOR FURTHER INFORMATION CONTACT:
Robert M. Marshall, at the above address (Telephone 602/379-4720).

SUPPLEMENTARY INFORMATION:

Background

    The cactus ferruginous pygmy-owl is a small bird, approximately 17 
centimeters (6\3/4\ inches) long. Males average 62 grams (g) [2.2 
ounces (oz)], females average 75 g (2.6 oz). It is reddish-brown 
overall, with a cream-colored belly streaked with reddish-brown. Some 
individuals are grayish, rather than reddish-brown. The eyes are 
yellow, the crown is lightly streaked, and there are no ear tufts. 
Paired black-and-white spots on the nape suggests eyes. The tail is 
relatively long for an owl, colored rufous with dark bars. The call of 
the diurnal owl, heard chiefly near dawn and dusk, is a monotonous 
series of short notes.
    The cactus ferruginous pygmy-owl (Order Strigiformes; Family 
Strigidae) is one of three 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 (Figure 1.). 
South of these regions and through Central America, G. b. ridgwayi 
replaces G. b. cactorum. Throughout South America, G. b. brasilianum is 
the resident subspecies (Fisher 1893, van Rossem 1937, Friedmann et al. 
1950, Schaldach 1963, Phillips et al. 1964, de Schauensee 1966, Karalus 
and Eckert 1974, Oberholser 1974, Johnsgard 1988).

BILLING CODE 4310-55-M

TP12DE94.001

BILLING CODE 4310-55-C
    The cactus ferruginous pygmy-owl (hereafter ``pygmy-owl,'' unless 
otherwise noted) was described by van Rossem (1937), based on specimens 
from Arizona and Sonora. It is distinguished from G. b. ridgwayi and G. 
b. brasilianum by its shorter wings and longer tail, and by generally 
lighter coloration (van Rossem 1937, Phillips et al. 1964). G. b. 
cactorum occurs in several color morphs, with distinct differences 
between regional populations (Sprunt 1955, Burton 1973, Tyler and 
Phillips 1978, Johnsgard 1988). Some investigators (e.g. van Rossem 
1937, Tewes 1992) have suggested that further taxonomic investigation 
is needed, primarily to determine whether the current G. b. cactorum 
comprises more than one subspecies. G. b. cactorum is widely recognized 
as a valid subspecies (e.g. Friedmann et al. 1950, Blake 1953, Sprunt 
1955, Phillips et al. 1964, Monson and Phillips 1981, Millsap and 
Johnson 1988, Binford 1989). The American Ornithologists' Union (AOU) 
recognized G. b. cactorum in its 1957 Checklist of North American Birds 
(AOU 1957), but subsequent lists did not include subspecies (AOU 1983). 
Based on these authorities, the Service accepted G. b. cactorum as a 
subspecies in 1991 (56 FR 58804), and again in 1993 (58 FR 13045).
    The pygmy-owl nests in a cavity in a tree or large columnar cactus. 
Cavities may be naturally formed (e.g. knotholes) or excavated by 
woodpeckers. No nest lining material is used. The pygmy-owl has also 
nested in fabricated nest boxes (S. Beasom, Texas Arts and Industries 
University, in litt.). Three, four, or sometimes five eggs are laid 
(Bent 1938, Heintzelman 1979) and incubated for approximately 28 days. 
The young fledge about 28 days after hatching. The pygmy-owl begins 
nesting activity in late winter to early spring. It is nonmigratory 
throughout its range (Bendire 1888, Griscom and Crosby 1926, Oberholser 
1974, Johnson et al. 1979). The pygmy-owl's diverse diet includes 
birds, lizards, insects, small mammals (Bendire 1888, Sutton 1951, 
Sprunt 1955, Earhart and Johnson 1970, Oberholser 1974), and even frogs 
and earthworms (S. Beasom, in litt.).
    The pygmy-owl occurs in a variety of subtropical scrub and woodland 
communities, including riverbottom woodlands, woody thickets 
(``bosques''), coastal plain oak associations, thornscrub, and 
desertscrub. Unifying habitat characteristics among these communities 
are fairly dense woody thickets or woodlands, with trees and/or cacti 
large enough to provide nesting cavities. Throughout its range, the 
pygmy-owl occurs at low elevations, generally below 1,200 meters (m) or 
4,000 feet (ft) (Swarth 1914, Karalus and Eckert 1974, Monson and 
Phillips 1981, Johnsgard 1988, Enriquez-Rocha et al. 1993). In southern 
Texas, the pygmy-owl's habitat includes coastal plain oak associations, 
and the Tamaulipan Thornscrub of the lower Rio Grande valley region, 
which is comprised of mesquite (Prosopis glandulosa), hackberry (Celtis 
spp.), oak (Quercus spp.), and Texas ebony (Pithecellobium ebano) 
(Griscom and Crosby 1926, Bent 1938, Oberholser 1974, Tewes 1992, Wauer 
et al. 1993). In northeastern Mexico, it occurs in lowland thickets, 
thornscrub communities, riparian woodlands, and second-growth forest 
(van Rossem 1945, AOU 1983, Tewes 1992, Enriquez-Rocha et al. 1993). In 
central and southern Arizona, the pygmy-owl's primary habitats are 
riparian cottonwood (Populus spp.) forests and mesquite bosques. Also 
in central and southern Arizona, the pygmy-owl occurs in Sonoran 
Desertscrub associations of paloverde (Cercidium spp.), bursage 
(Ambrosia spp.), ironwood (Olneya tesota), mesquite (Prosopis 
juliflora), acacia (Acacia spp.), and giant cacti like the saguaro 
(Cereus giganteus), and organpipe (Cereus thurberi) (Gilman 1909, Bent 
1938, van Rossem 1945, Phillips et al. 1964, Monson and Phillips 1981, 
Johnson-Duncan et al. 1988, Millsap and Johnson 1988). Farther south in 
northwestern Mexico, the pygmy-owl occurs in Sonoran Desertscrub, 
Sinaloan Thornscrub, and Sinaloan Deciduous Forest as well as 
riverbottom woodlands, cactus forests and thornforest (Enriquez-Rocha 
et al. 1993, G. Monson in prep.).
    The available information indicates that distinct eastern and 
western populations of the pygmy-owl may be defined (Figure 1.). The 
pygmy-owl occurs along the lower Rio Grande River and the coastal plain 
of southern Texas and northeastern Mexico. It also occurs in lowland 
areas of northwestern Mexico and southern Arizona. The pygmy-owl's 
elevational distribution, the distribution of habitat, and recorded 
locations indicate that these eastern and western ranges of the pygmy-
owl are geographically isolated from one another and are ecologically 
distinct. In the U.S., the eastern and western portions of the pygmy-
owl's range are separated by the basin-and-range mountains and 
intervening Chihuahuan Desert basins of southeastern Arizona, southern 
New Mexico, and western Texas. Although Grossman and Hamlet (1964) 
suggested that the pygmy-owl's range included this U.S.-Mexico border 
region, the pygmy-owl has never been recorded in this 500-mile (mi) 
wide area (Bailey 1928, Phillips et al. 1964, Oberholser 1974, S.O. 
Williams, New Mexico Department of Game and Fish, in litt.).
    In Mexico, the eastern and western populations are separated by the 
highlands of the Sierra Madre Oriental and Occidental, and the Mexican 
Plateau. The pygmy-owl is considered rare on the Mexican Plateau and/or 
above elevations of 1,200 m (4,000 ft) on the west, and above 330 m 
(1,000 ft) on the east (Friedman et al. 1950). Some sources describe 
the eastern and western ranges as contiguous at the southern end of its 
range, near the southern end of the Mexican Plateau in central Mexico 
(Johnsgard 1988). Other sources (e.g., Burton 1973) describe these two 
ranges as being disjunct. In his description of the subspecies, van 
Rossem (1937) found that Texas specimens exhibited characteristics of 
both G. b. cactorum and G. b. ridgwayi. Ultimately, he did not assign 
Texas ferruginous pygmy-owls to G. b. cactorum, noted that Ridgway 
(1914, in van Rossem 1937) considered them distinct from G. b. 
ridgwayi, and left the taxonomy of Texas G. brasilianum open. Most 
authors have subsequently considered Texas pygmy-owls to be G. b. 
cactorum (e.g., Oberholser 1974, Millsap and Johnson 1988).
    In addition to geographic separation, the pygmy-owl's eastern and 
western populations occupy different habitats. Although some broad 
similarities in habitat physiognomy are apparent (e.g., dense woodlands 
and thickets), floristically these eastern and western habitats are 
very dissimilar. The desertscrub and thornscrub associations in Arizona 
and western Mexico are unlikely any habitats occupied by the pygmy-owl 
in eastern Mexico and southern Texas. Also, the oak association habitat 
occupied on coastal plains in southern Texas is unlike any habitat 
available in the western portion of the pygmy-owl's range. However, the 
Tamaulipan thornscrub habitat of the east and the riverbottom mesquite-
cottonwood bosque habitat once found in Arizona are more similar in 
physiognomy and to a slight degree in floristic makeup.
    The potential for genetic distinctness further supports identifying 
eastern and western pygmy-owl populations. The fact that the pygmy-owl 
is nonmigratory throughout its range suggests that genetic mixing 
across wide areas may be infrequent. Considerable variation in plumage 
between regional populations has been noted, including specific 
distinctions between Arizona and Texas pygmy-owls (van Rossem 1937, 
Burton 1973, Tyler and Phillips 1978, Johnsgard 1988).
    The above information indicates that eastern and western 
populations of the cactus ferruginous pygmy-owl are distinct, based on 
geographic isolation, potential morphological and genetic distinctness, 
and distribution and status of habitat. These eastern and western 
populations of the pygmy-owl may be considered separately for listing 
under the Act, as ``* * * any subspecies * * * and any distinct 
population segment of any species of vertebrate which interbreeds when 
mature'' [Section 3(16)]. Further, the status of the species in Mexico 
is currently unclear (see discussion under ``Factor A'', below).
    The above criteria lead the Service to consider four separate 
populations of G. b. cactorum for listing purposes: western U.S. 
(Arizona), eastern U.S. (Texas), western Mexico, and eastern Mexico. 
Because the levels of threat, habitats occupied, quality of 
information, and overall status differ among these four populations, 
the Service herein proposes separate actions for various population 
segments.
    The Service included the pygmy-owl on its Animal Notice of Review 
as a category 2 candidate species throughout its range on January 6, 
1989 (54 FR 554). After soliciting and reviewing additional 
information, the Service elevated G. b. cactorum to category 1 
candidate status throughout its range on November 21, 1991 (56 FR 
58804). A category 1 species is one for which the Service has on file 
substantial information to support listing, but a proposal to list has 
not been issued because it is precluded at present by other listing 
activity.
    Based on an extensive review of information on the species, it is 
now appropriate to list the U.S. populations, while continuing to 
review the species in Mexico to determine whether Mexican populations 
should be proposed for listing. Recent information from Mexico 
indicates that the species may be more abundant, at least in the 
southern portion of its range, than originally thought.
    On May 26, 1992, a coalition of conservation organizations (Galvin 
et al. 1992) petitioned the Service, requesting listing of the pygmy-
owl as an endangered species under the Act. The petitioners also 
requested designation of critical habitat. In accordance with Section 
4(b)(3)(A) of the Act, on March 9, 1993, the Service published a 
finding that the petition presented substantial scientific or 
commercial information indicating that listing may be warranted, and 
commenced a status review on the pygmy-owl (58 FR 13045). In conducting 
its status review, the Service solicited additional comments and 
biological data on the status of the cactus ferruginous pygmy-owl, 
through mailings, a notice in the Federal Register (58 FR 13045), and 
other means.
    Section 4(b)(3)(B) of the Act requires the Secretary of the 
Interior to reach a final decision on any petition accepted for review 
within 12 months of its receipt (16 U.S.C. Sec. 1531 et seq.). That 
decision, to be published in the Federal Register, must be one of the 
following findings: (1) The petitioned action is not warranted; (2) the 
petitioned action is warranted (a proposed regulation is published); or 
(3) the petitioned action is warranted, but the immediate proposal is 
precluded by listing actions of higher priority. This proposal 
constitutes a 1-year finding with respect to the petition that listing 
as endangered is warranted for the Arizona population, listing as 
threatened is warranted for the Texas population, and listing is not 
now warranted for the two populations in Mexico.
    Since designating the pygmy-owl as a category 1 species, in the 
course of its continuing status review, the Service has acquired 
significant new information on the cactus ferruginous pygmy-owl. This 
finding is based on various documents, including published and 
unpublished studies, agency documents, and field survey records. All 
documents on which this finding is based are on file in the Fish and 
Wildlife Service Ecological Service State Office in Phoenix, Arizona. 
For an explanation of the relationship between petition findings and 
candidate category status, see 58 FR 28034 (May 12, 1993).

Summary of Factors Affecting the Species

    Section 4(a)(1) of the Act and regulations (50 CFR Part 424) 
promulgated to implement the listing provisions of the Act set forth 
the procedures for adding species to the Federal List of Endangered and 
Threatened Wildlife and Plants. A species may be determined to be an 
endangered or threatened species owing to one or more of the five 
factors described in Section 4(a)(1). These factors and their 
application to the cactus ferruginous pygmy-owl (Glaucidium brasilianum 
cactorum) are as follows:
    A. The present or threatened destruction, modification, or 
curtailment of its habitat or range. The cactus ferruginous pygmy-owl 
is threatened by past, present, and potential future destruction and 
modification of its habitat, throughout a significant portion of its 
range in the U.S., and, to a less well-known extent, in portions of its 
range in Mexico (Phillips et al. 1964, Oberholser 1974, Johnson et al. 
1979, Monson and Phillips 1981, Johnson and Haight 1985a, Hunter 1988, 
Millsap and Johnson 1988, Tewes 1992). The severity of habitat loss and 
threats varies across the pygmy-owl's range. It has been virtually 
extirpated from Arizona, which once constituted its major U.S. range 
(see Figure 1). In Texas, the pygmy-owl has been virtually extirpated 
from the lower Rio Grande valley, but persists in oak associations on 
the coastal plain north of the Rio Grande valley. The majority of these 
losses are because of destruction and modification of riparian and 
thornscrub habitats. Wide-scale loss and modification of up to 90 
percent of riparian habitats in the southwestern U.S. have occurred 
(e.g. Phillips et al. 1964, Carothers 1977, Kusler 1985, General 
Accounting Office 1988, Jahrsdoerfer and Leslie 1988, Szaro 1989, Dahl 
1990, State of Arizona 1990, Bahre 1991). These losses are attributed 
to urban and agricultural encroachment, woodcutting, water diversion, 
channelization, livestock overgrazing, groundwater pumping, and 
hydrological changes resulting from various land-use practices. Status 
information for Mexico is very limited, but some observations suggest 
that although habitat loss and reduced numbers are likely to have 
occurred in northern portions of the two populations in Mexico, the 
pygmy-owl persists as a locally common bird in southern portions. 
Habitat loss and population status are summarized below for the four 
populations of the pygmy-owl.

Western Populations

    Several habitat types are used by the pygmy-owl in the western 
portion of its range. These include riparian woodlands and bosques 
dominated by mesquite and cottonwood, Sonoran Desertscrub (usually with 
relatively dense saguaro cactus forests), Sinaloan Thornscrub, and 
Sinaloan Deciduous Forest (van Rossem 1945, Phillips et al. 1964, 
Karalus and Eckert 1974, Millsap and Johnson 1988, Monson and Russell 
in prep.).

1. Arizona

    The northernmost record for the pygmy-owl is from New River, 
Arizona, approximately 55 kilometers (km) (35 mi) north of Phoenix, 
where Fisher (1893) found it to be ``quite common'' in thickets of 
intermixed mesquite and saguaro cactus. Prior to the mid-1900's, the 
pygmy-owl was also described as a ``common,'' ``abundant,'' ``not 
uncommon,'' and ``fairly numerous'' resident of lowland central and 
southern Arizona, in cottonwood forests, mesquite-cottonwood woodlands, 
and mesquite bosques along the Gila, Salt, Verde, San Pedro, and Santa 
Cruz Rivers, and various tributaries (Coues 1872, Bendire 1888, 
Breninger 1898 in Bent 1938, Gilman 1909, Swarth 1914, Friedmann et al. 
1950, Phillips et al. 1964, Johnson and Simpson 1971, Millsap and 
Johnson 1988). The pygmy-owl also occurs in Sonoran Desertscrub 
associations in southern and southwestern Arizona, comprised of 
paloverde, ironwood, mesquite, acacia, bursage, and columnar cacti like 
the saguaro and organpipe (Phillips et al. 1964, Davis and Russell 1984 
and 1990, Monson and Phillips 1981, Johnson and Haight 1985a). the 
pygmy-owl's occurrence in Sonoran Desertscrub has apparently always 
been uncommon and unpredictable.
    However, it seems to be more predictably found in xeroriparian 
habitats (very dense desertscrub thickets bordering dry desert washes) 
than more open desert uplands (Monson and Phillips 1981, Johnson and 
Haight 1985a, Johnson-Duncan et al. 1988, Millsap and Johnson 1988, 
Davis and Russell 1990). The pygmy-owl may also occur at isolated 
desert oases which support small pockets of riparian or xeroriparian 
vegetation (Howell 1916, Phillips et al. 1964).
    The above habitats are likely to provide several requirements of 
pygmy-owl ecology. Trees and large cacti provide cavities for nesting 
and roosting. Also, these habitats along watercourses are known for 
their high density and diversity of animal species that constitute the 
pygmy-owl's prey base (Carothers 1977, Johnson et al. 1977, Johnson and 
Haight 1985b, Stromberg 1993).
    The pygmy-owl has declined throughout Arizona to the degree that it 
is now virtually extirpated from the State [Johnson et al. 1979, Monson 
and Phillips 1981, Arizona Game and Fish Department (AGFD) 1988, 
Johnson-Duncan et al. 1988, and Millsap and Johnson 1988]. Riverbottom 
forests and bosques, which supported the greatest abundance of pygmy-
owls, have been extensively modified and destroyed by clearing, 
urbanization, water management, and hydrological changes (Willard 1912, 
Brown et al. 1977, Rea 1983, Szaro 1989, Bahre 1991, Stromberg et al. 
1992, Stromberg 1993). Cutting for domestic and industrial fuelwood was 
so extensive throughout southern Arizona that, by the late 19th 
century, riparian forests within tens of miles of towns and mines had 
been decimated (Bahre 1991). Mesquite was a favored species, because of 
its excellent fuel qualities. The famous, vast forests of ``giant 
mesquites'' along the Santa Cruz River in the Tucson area described by 
Swarth (1905) and Willard (1912) fell to this threat, as did the 
``heavy mesquite thickets'' where Bendire (1888) collected pygmy-owl 
specimens along Rillito Creek, a Santa Cruz River tributary, also in 
what is now Tucson. Only remnant fragments of these bosques remain. 
Cottonwoods were also felled for fuelwood, fenceposts, and for the 
bark, which was used as cattle feed (Bahre 1991). In recent decades, 
the pygmy-owl's riparian habitat has continued to be modified and 
destroyed by agricultural development, woodcutting, urban expansion, 
and general watershed degradation (Brown et al. 1977, Phillips et al. 
1964, State of Arizona 1990, Bahre 1991, Stromberg et al. 1992, 
Stromberg 1993).
    The trend of Sonoran Desertscrub habitats and pygmy-owl occupancy 
is not as clear. Historical records from this habitat in Arizona are 
few. This may be due to disproportionate collecting along rivers where 
humans were concentrated, while the upland deserts were less 
intensively surveyed. Johnson and Haight (1985a) suggested that the 
pygmy-owl adapted to upland cactus associations and xeroriparian 
habitats in response to the demise of Arizona's riverbottom woodlands. 
However, conclusive evidence to support this hypothesis is not 
available. It may be that desertscrub habitats simply are of lesser 
quality, and have always been occupied by pygmy-owls at lower frequency 
and density (Johnson and Haight 1985b, Taylor 1986). The few pygmy-owls 
located in recent years have been fairly evenly distributed between 
remaining riverbottom woodlands, desertscrub, and xeroriparian 
habitats. Sonoran Desertscrub has been affected to varying degrees by 
urban and agricultural development, woodcutting, and livestock grazing 
(Bahre 1991).
    Hunter (1988) found fewer than 20 verified records of pygmy-owls in 
Arizona for the period of 1971 to 1988. In 1992, surveys located three 
single pygmy-owls in Arizona (Fish and Wildlife Service and National 
Park Service, unpubl. data, SWCA, Inc. 1993). In 1993, more extensive 
surveys again located three single pygmy-owls in Arizona (Felley and 
Corman 1993, AGFD and Service, unpubl. data). Although G. b. cactorum 
is diurnal and frequently vocalizes in the morning, the species was not 
recorded or reported in breeding bird survey data (Robbins et al. 
1986).
    In addition to clearing woodlands, the diversion and channelization 
of natural watercourses, and pumping groundwater, are also likely to 
have reduced G. b. cactorum habitat. Diversion and pumping result in 
diminished surface flows, and consequent reductions in riparian 
vegetation are likely (Brown et. al. 1977, Strombery et al. 1992, 
Stromberg 1993). Channelization often alters stream banks and fluvial 
dynamics necessary to maintain native riparian vegetation. The series 
of dams along most major southwestern rivers (e.g., the Colorado, Gila, 
Salt, Verde) have altered riparian habitat downstream of dams through 
hydrological and vegetational changes, and have inundated habitat 
upstream.
    Overuse by livestock has been a major factor in the degradation and 
modification of riparian habitat in the western U.S. These effects 
include changes in plant community structure and species composition 
and relative abundance of species and plant density. These changes are 
often linked to more widespread changes in watershed hydrology (Brown 
et al. 1977, Rea 1983, GAP 1988). These changes are likely to affect 
the habitat characteristics critical to G. b. cactorum. Livestock 
grazing in riparian habitats is one of the most common causes of 
riparian degradation (e.g., Ames 1977, Carothers 1977, Behnke and 
Raleigh 1978, General Accounting Office 1988, Forest Service 1979).
    Potential future threats to pygmy-owl habitat also exist. Expanding 
human populations in the border region are expected to continue to 
increase impacts and threats discussed above. Further, extensive 
industrial, municipal, and agricultural developments facilitated by the 
Northern American Free Trade Agreement are anticipated along the U.S.-
Mexico border. These developments may result in accelerated habitat 
loss and demands on groundwater.

2. Western Mexico

    The pygmy-owl occurs in the more arid lower elevations (below 1,200 
m (4,000 ft) elevation) in western Mexico, in riparian woodlands and 
communities of thornscrub and large cacti. The pygmy-owl is absent or 
rare in the highlands of Mexico's central plateau (Friedmann et al. 
1950), where the least (G. minustissima) and northern (G. qnoma) pygmy-
owls occur.
    In the mid-20th century, the pygmy-owl was generally described as 
having been common in western Mexico (van Rossem 1945, Friedmann et al. 
1950, Blake 1953). Schaldach (1963) considered the pygmy-owl abundant 
in Colima, at the southern extreme of its range, 30 years ago. Fifth 
years ago, the pygmy-owl was considered ``fairly common'' in the lower 
elevations of western Sonora (van Rossem 1945). Current information on 
the status of the pygmy-owl and its habitat in western Mexico is 
incomplete, but suggests that trends vary within different geographic 
areas. The pygmy-owl can still be located fairly easily in southern 
Sonora (Babbitt 1985, T. Corman, AGFD, pers. comm.), but its 
distribution is somewhat erratic. Christmas Bird Count data from 1972 
through 1991 from Alamos, Sonora, and San Blas, Nayarit, indicate that 
the pygmy-owl was not uncommon, but detections varied widely from year 
to year (National Audubon Society 1972-1992). In recent years it has 
been found in abundance in some areas but is absent in others, in 
apparently similar habitat. Abundance also varies between habitat 
types, being more abundant in thorn forest than cactus forest (Taylor 
1986). The pygmy-owl is now rare or absent in northern Sonora, within 
150 miles of the U.S.-Mexico border (Hunter 1988, Monson and Russell in 
prep., AGFD in litt.). Extensive conversion of desertscrub and 
thornscrub to the exotic bufflegrass (Cenchrus ciliarus) for livestock 
forage is known to be taking place, but quantification is not currently 
available. It is possible that the factors causing declines in Arizona 
are also having effects in western Mexico (Deloya 1985, Hunter 1988). 
However, further information is needed before determining whether it 
should be listed in western Mexico.

Eastern Populations

    Several habitat types are also used by the pygmy-owl in the eastern 
portion of its range. These include coastal plain oak associations in 
south Texas (Tewes 1992, Wauer et al. 1993), Tamaulipan Thornscrub in 
the lower Rio Grande valley and other lowland areas, and thick forest 
and second-growth forest in Nuevo Leon and Tamaulipas.

1. Texas

    The pygmy-owl's historical range in Texas included the lower Rio 
Grande valley, where it was considered a common resident of dense 
mesquite-cottonwood-ebony woodlands and Tamaulipan brushland (Griscom 
and Crosby 1926, Bent 1938, Friedmann et al. 1950, Stillwell and 
Stillwell 1954, Oberholser 1974, Millsap and Johnson 1988). The pygmy-
owl also occurs in coastal plain oak associations between Brownsville 
and Corpus Christi (Oberholser 1974), where it has recently been found 
in significant numbers (Wauer et al. 1993, S. Beasom in litt., P. 
Palmer in litt.).
    The pygmy-owl has declined throughout a significant portion of its 
Texas range (Oberholser 1974, Johnson et al. 1979, Johnson and Haight 
1985a, Millsap and Johnson 1988, Tewes 1992). It appears to persist in 
relatively high numbers in coastal plain oak associations north of the 
lower Rio Grande valley (Wauer et al. 1993). The pygmy-owl was 
described as a common breeding bird in the lower Rio Grande valley near 
Brownville in the early 1900's (Griscom and Crosby 1926, Friedmann et 
al. 1950), but was considered to have become rare in that region by 
mid-century (Wolfe 1956, Oberholser 1974). Pygmy-owls have been seen 
less frequently in recent years and in fewer numbers (Oberholser 1974, 
Hunter 1988, Wauer et al. 1993). Tewes (1992) found no pygmy-owls in a 
1991 survey of the lower Rio Grande valley, but sporadic reports of 
single birds continue.
    Habitat has been, and continues to be, lost and modified along the 
lower Rio Grande valley, chiefly through agricultural development and 
urban expansion. Since the early 1900's, approximately 95 percent of 
native Tamaulipan Brushland in the lower Rio Grande valley has been 
cleared for agriculture, urban development, and recreation 
(Jahrsdoerfer and Leslie 1988). By reducing river flow, water 
development has further altered or destroyed brushland in riparian 
areas.
    Impacts on coastal oak associations are less well known, but appear 
to be lesser. Limited oak clearing has taken place, but extensive 
habitat remains. Little net quantitative change in this habitat appears 
to have occurred in the last 100 years, and the habitat may have 
increased in the late 1600's and early 1700's (Wauer et al. 1993, P. 
Palmer in litt.). Pygmy-owls are currently found in this habitat in 
their greatest numbers in the U.S.
    Other causes of habitat decline in Texas include alteration of 
water regimes and overuse by livestock, both of which have degraded the 
riparian ecosystems of the lower Rio Grande (see discussion of these 
factors under ``Arizona'', above). However, in a nonriparian grassland/
woodland mosaic in Texas, Wauer et al. (1993) believed livestock 
grazing may have increased pygmy-owl habitat by suppressing grasslands 
and allowing encroachment by oak associations.
    Potential future threats to pygmy-owl habitat also exist. In 
coastal Texas, placement of spoil from offshore dredging operations may 
impact coastal oak associations. Expanding human populations in the 
border region are expected to continue to increase impacts and threats 
discussed above. Further, extensive industrial, municipal, and 
agricultural developments facilitated by the North American Free Trade 
Agreement are anticipated along the U.S.-Mexico border. These 
developments may result in accelerated habitat loss and demands on 
groundwater.

2. Eastern Mexico

    The pygmy-owl occurs in lowland regions [below 330 m (1,000 ft)] 
along the Gulf Coast of northeastern Mexico (Friedmann et al. 1950), in 
the States of Tamaulipas and Nuevo Leon. Its primary habitat in this 
region is Tamaulipan thornscrub, forest edge, riparian woodlands, 
thickets, and lowland tropical deciduous forest (Webster 1974, Tewes 
1992, Enriquez-Rocha et al. 1993). The pygmy-owl is absent or rare in 
the highlands of Mexico's central plateau (Friedmann et al. 1950), 
where the least and northern pygmy-owls occur.
    In the mid-20th century, the pygmy-owl was generally described as 
having been common in eastern Mexico (Friedmann et al. 1950, Blake 
1953). Current information on the status of the pygmy-owl and its 
habitat in eastern Mexico is incomplete. In 1976, the pygmy-owl was 
reported to be ``fairly common'' in the Sierra Picachos of Nuevo Leon 
(Arvin 1976). In 1991, Texas (1992) located pygmy-owls at 13 of 27 
survey sites in northeastern Mexico. Tewes (1992) believed expansion of 
the human population could reduce available habitat in the region 
surveyed, but also noted that pygmy-owls were found within larger towns 
in the region. Wauer et al. (1993) believed no populations in 
northeastern Mexico appeared to be sizable enough to provide 
recruitment for other areas. Christmas Bird Count data from 1972 
through 1992 from Rio Corona and Gomez Farias, both in Tamaulipas, 
indicate the pygmy-owl was not uncommon, but detections varied widely 
from year to year (National Audubon Society 1972-1992). Christmas Bird 
Count data indicated the same for ferruginous pygmy-owls at El Naranjo 
in San Louis Potosi, at the zone of probably intergradation between 
G.b. cactorum and G.b. ridgwayi. It is possible that the factors 
causing declines in Texas are also having effects in Mexico (Deloya 
1985, Hunter 1988). However, further information on the subspecies is 
needed before determining whether it should be listed in eastern 
Mexico.
    B. Overutilization for commercial, recreational, scientific, or 
educational purposes. The pygmy-owl is highly sought by bird watchers, 
who concentrate at several of the remaining known locations of pygmy-
owls in the U.S. While limited, careful bird watching is probably not 
harmful, excess attention by bird watchers may at times constitute 
harassment, affecting the occurrence and behavior of the pygmy-owl 
(Oberholser 1974, Tewes 1992). For example, in early 1993, one of the 
few areas in Texas known to support the pygmy-owl continued to be 
widely publicized (American Birding Association 1993). The resident 
pygmy-owls were not detected at this highly-visited area after early in 
the breeding season. The Service is unaware of any other overuse, for 
any purpose, which constitutes a threat to the pygmy-owl.
    c. Disease or predation. The Service is unaware of any disease or 
predation which constitutes a significant threat to G. b. cactorum.
    D. The inadequacy of existing regulatory mechanisms. The Migratory 
Bird Treaty Act (MBTA) (16 U.S.C. 703-712) is the only direct, current 
Federal protection provided for the cactus ferruginous pygmy-owl. The 
MBTA prohibits ``take'' of any migratory bird. ``Take'' is defined as 
``* * * to pursue, hunt, shoot, wound, kill, trap, capture, or collect, 
or attempt to pursue, hunt, shoot, wound, kill, trap, capture, or 
collect.'' However, unlike the Endangered Species Act, there are no 
provisions in the MBTA preventing habitat destruction unless direct 
mortality or destruction of active nests occurs.
    The Federal Clean Water Act contains provisions for regulating 
impacts to river systems and their tributaries. These mechanisms have 
been insufficient to prevent major losses of riparian habitat, 
including habitats occupied by the pygmy-owl.
    The State of Arizona lists the ferruginous pygmy-owl (subspecies 
not defined) as endangered (AGFD 1988). However, this designation does 
not provide special regulatory protection. Arizona regulates the 
capture, handling, transportation, and take of most wildlife, including 
G. b. cactorum, through game laws, special licenses, and permits for 
scientific investigation. However, habitat is not protected under 
Arizona endangered species law.
    The State of Texas lists the ferruginous pygmy-owl (subspecies not 
defined) as threatened (Texas Parks and Wildlife Department 1978 and 
1984). This designation requires permits for take for propagation, 
zoological gardens, aquariums, rehabilitation purposes, and scientific 
purposes (State of Texas 1991). Again, however, there are no provisions 
for habitat protection. The pygmy-owl is also on the Texas Organization 
for Endangered Species' (TOES) ``watch list'' (TOES 1984).
    Most Federal agencies have policies to protect species listed by 
States as threatened or endangered, and some also protect species that 
are candidates for Federal listing. For example, the National Park 
Service protects all wildlife within most National Parks and Monuments. 
However, until agencies develop specific protection guidelines, 
evaluate their effectiveness, and institutionalize their 
implementation, it is uncertain whether any general agency policies 
adequately protect the pygmy-owl and its habitat.
    No conservation plans or habitat restoration projects specific to 
the cactus ferruginous pygmy-owl exist for lands managed by the U.S. 
Government, Indian Nations, State agencies, or private parties. The 
Forest Service, Bureau of Land Management, and Bureau of Reclamation 
have focussed some attention on modifying livestock grazing practices 
in recent years, particularly as they affect riparian ecosystems. 
Several of those projects are in the former range of G. b. cactorum, 
including some historical nesting locations. In addition, some private 
landowners in Southern Texas are accommodating research and have 
expressed interest in carrying out conservation measures to benefit the 
pygmy-owl.
    E. Other natural or manmade factors affecting its continued 
existence. The riparian woodland habitat of G. b. cactorum was always 
rare and has become even more so. Its habitat rarity, and small, 
isolated populations make the remaining G. b. cactorum increasingly 
susceptible to local extirpation through land development, predation, 
and stochastic events such as catastrophic floods and fires.
    The disjunct nature of habitats, small breeding populations, and 
nonmigratory status may also impede the flow of genetic material 
between populations and reduce the chance of demographic and genetic 
rescue from immigration for adjacent populations. The resulting 
constraints on the gene pool intensify the external threats to the 
pygmy-owl.
    The pygmy-owl's occurrence in floodplain areas that are now largely 
agricultural may indicate a potential threat from pesticides. Where 
populations remain, they are sometimes in proximity to agricultural 
areas, with associated pesticides and herbicides. Without appropriate 
precautions, these agents may potentially affect G. b. cactorum through 
direct toxicity or effects on their food base. No quantitative data on 
this potential threat are known at this time.
    This pygmy-owl nests in cavities excavated by woodpeckers in trees 
or large cacti. Some sources (AGFD 1988) believe that increasing 
competition with the exotic European starling for nest cavities may be 
a threat to cavity nesters like the pygmy-owl.
    The Service has carefully assessed the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by this species in determining to propose this 
rule. Based on this evaluation, the preferred action is to list the 
cactus ferruginous pygmy-owl (Glaucidium brasilianum cactorum) as 
endangered in Arizona, where it is nearly extirpated and is in imminent 
danger of imminent danger of disappearing, and as threatened in Texas, 
where it has undergone significant decline but is not in danger of 
extinction. The Service will continue to review the status of the 
species in Mexico.

Critical Habitat

    Critical habitat, as defined by Section 3 of the Act, means:
    (i) The specific areas within the geographical area occupied by a 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features (I) essential to the 
conservation of the species and (II) that may require special 
management considerations or protection, and
    (ii) Specific areas outside the geographical area occupied by a 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Section 4(a)(3) of the Act requires that critical habitat be 
designated to the maximum extent prudent and determinable concurrently 
with the determination that a species is endangered or threatened. 
Critical habitat is being proposed for the cactus ferruginous pygmy-owl 
to include riparian thickets, forests, and woodlands along streams, 
rivers, and ephemeral drainages in Arizona. The following areas 
proposed as critical habitat (all legal descriptions are from the Gila 
and Salt River Meridian):
    1. Arizona, Maricopa County: approximately 21 km (13 mi) along the 
Salt River, from Stewart Mountain Dam to Granite Reef Dam.
    2. Arizona, Maricopa County: approximately 39 km (24 mi) along the 
Verde River, from Bartlett Dam to the confluence of the Verde and Salt 
Rivers.
    3. Arizona, Cochise, Pima, and Pinal Counties: approximately 97 km 
(60 mi) along the San Pedro River, from the confluence of Soza Canyon 
to the confluence of the San Pedro and Gila Rivers, including Cook's 
Lake.
    4. Arizona, Pima County: approximately 42 km (26 mi) along the 
Santa Cruz River, from the Interstate 19 bridge downstream to the Avra 
Valley Road bridge.
    5. Arizona, Pima County: approximately 54 km (34 mi) along the 
Rillito Creek system, from the confluence of Rillito Creek and the 
Santa Cruz River upstream, along Tanque Verde Creek to the boundary 
between sections 2 and 3, Township 14 south, Range 16 east, and 
upstream along Agua Caliente Creek to the Soldier Trail crossing.
    6. Arizona, Pima County: approximately 23 km (14 mi) along Canada 
del Oro, from its confluence with Sutherland Wash downstream to its 
confluence with the Santa Cruz River.
    7. Arizona, Pima County: approximately 45 km (28 mi) along Alamo 
Wash and Growler Wash, from the well in Alamo Canyon (T16S, R4W, 
unsurveyed Section 6) downstream to the point where Growler Wash 
intersects the Bates Well Road.
    8. Arizona, Pima County: approximately 13 km (8 mi) along Arivaca 
Creek, from the road crossing in the town of Arivaca downstream to the 
confluence with San Luis Wash.
    9. Arizona, Greenlee and Graham Counties: approximately 27 km (17 
mi) along the Gila River, from the confluence with the San Francisco 
River downstream to the gaging station in Section 31, Township 6 South, 
Range 28 East Meridian.
    10. Arizona, Pinal and Graham Counties: approximately 69 km (43 mi) 
along the Gila River, from the confluence with the San Pedro River 
downstream to the Ashurst-Hayden Dam.
    11. Arizona, Graham County: approximately 10 km (6 mi) along Bonita 
Creek, from the boundary between Section 36, Township 5 South, Range 27 
East, and Section 31, Township 5 South, Range 28 East, downstream to 
the confluence of Bonita Creek and the Gila River.
    12. Arizona, Maricopa County: approximately 27 km (17 mi) along the 
New River, from the boundary between Sections 3 and 4, Township 7 
North, Range 3 East, downstream to the boundary between Sections 19 and 
20, Township 6 North, Range 2 East.
    A total of approximately 467 km (290 mi) of stream and river, 
including the 100-year floodplain and 100 meters laterally adjacent to 
the 100-year floodplain, is being proposed as critical habitat. The 
areas described were chosen for critical habitat designation because 
they contain historical and/or current locations for the cactus 
ferruginous pygmy-owl, and/or have the potential to support nesting 
cactus ferruginous pygmy-owls. All areas contains, or with recovery 
will contain, suitable nesting habitat. All areas contain some 
unoccupied habitat or former (degraded) habitat, which is needed to 
recover ecosystem integrity and support larger numbers of the owl 
during its recovery.
    The areas proposed for critical habitat are on lands owned and 
managed by the Service, the National Park Service, the Bureau of Land 
Management, the U.S. Forest Service, the Fort McDowell Indian 
Reservation, the Salt River Indian Reservation, the State of Arizona, 
and private parties. The majority of proposed critical habitat is on 
lands owned or managed by the Bureau of Land Management, the State of 
Arizona, and private parties.
    The Service is required to base critical habitat proposals on the 
best available scientific information (50 CFR Sec. 424.12). In 
determining what areas to propose as critical habitat, the Service 
considers those physical and biological features that are essential to 
the conservation of the species and that may require special management 
considerations or protection (primary constituent elements). Species 
requirements include, but are not limited to, the following: (1) Space 
for individual and population growth; (2) food, water, air, light, 
minerals, or other nutritional or physiological requirements; (3) cover 
or shelter; (4) sites for breeding, reproduction, rearing of offspring, 
germination, or seed dispersal; and, generally, (5) habitats that are 
protected from disturbance or are representative of the historical 
geographical and ecological distributions of a species. Primary 
constituents elements of critical habitat may include, but are not 
limited to, the following: Roost sites, nesting grounds, spawning 
sites, feeding sites, seasonal wetland or dryland, water quality or 
quantity, host species or plant pollinators, geological formation, 
vegetation type, tide, and specific soil types.
    The Service is proposing to designate as critical habitat areas 
which provide, or with rehabilitation will provide, the above physical 
and biological features and primary constituent elements. In 
determining biologically appropriate areas to propose for designation 
as critical habitat, the Service focuses on the primary constituent 
elements that are essential to the conservation of the species, without 
consideration of land or water ownership or management.
    The Service is required to list the primary constituent elements 
for any critical habitat that is proposed. For all areas of critical 
habitat proposed here, the above features and elements are provided or 
will be provided by thickets, forests, woodlands, thornscrub, and 
desertscrub that are inhabited or potentially habitable for the primary 
biological needs of foraging, nesting, rearing of young, roosting, and 
sheltering. Constituent elements include riparian forests, riverbottom 
woodlands, and xeroriparian thickets within or bordering the designated 
drainages. Woodlands, thickets, and desertscrub associations adjacent 
to these floodplain areas also provide primary constituent elements. 
Specific plant associations include those dominated by cottonwood, 
mesquite, and Sonoran Desertscrub/Thornscrub. These plant associations 
are characterized by, but are not limited to, the following plant 
species, in any combination: cottonwood, willow (Salix spp.), ash, 
mesquite, paloverde, ironwood, saguaro cactus, organpipe cactus, 
cresotebush (Larrea spp.), acacia, and hackberry, and areas where such 
vegetation may become established. These associations attain their 
greatest development, and support the highest numbers of pygmy-owls, in 
the approximate 100-year floodplain zone of river drainages.
    The presence of surface or subsurface water is critical in 
maintaining the majority of pygmy-owl habitat. The thicket, woodland, 
and forest communities described above are largely dependent on 
availability of groundwater at or near the soil surface. Surface or 
subsurface moisture may also be important in maintaining various 
species comprising the pygmy-owl's prey base.
    The above primary constituent elements are interrelated in the life 
history of the cactus ferruginous pygmy-owl. These relationships were 
major considerations in selection of proposed critical habitat. In 
addition to the above primary constituent elements, several other 
selection criteria were used to determine areas necessary for the 
survival and recovery of the pygmy-owl. These were: (1) Areas where 
pygmy-owls were historically recorded as occurring; (2) areas adjacent 
to or near those where pygmy-owls were historically recorded as 
occurring that provide or provided the same constituent elements; and 
(3) areas pygmy-owls are currently known to occur.
    Not all areas likely to have been occupied historically, or likely 
to be occupied now, have been proposed for designation as critical 
habitat. The critical habitat areas proposed are those that the Service 
believes are necessary for the survival and recovery of the pygmy-owl 
and in need of special management or protection. For example, in 
Sonoran Desertscrub habitat of upland areas in southern Arizona, the 
pygmy-owl apparently has always been uncommon to rare and unpredictable 
in occurrence. The Service believes this desert habitat has always been 
of peripheral or marginal importance to pygmy-owls in Arizona, and that 
the habitats necessary for the survival and recovery of the pygmy-owl 
are those along major riverbottoms, where the species was historically 
common. Therefore, sections of major rivers have been proposed as 
critical habitat, but Sonoran Desert habitats, in general, have not. 
However, pygmy-owls will still receive protection under Sections 7 and 
9 of the Act, regardless of whether they occur in critical habitat.
    Designation of critical habitat is not prudent when the species is 
threatened by taking or other human activity, and identification of 
critical habitat can be expected to increase the degree of such threat, 
or when designation of critical habitat would not be beneficial to the 
species [50 CFR 424.12(a)(1)].
    Because the Service is currently working cooperatively with private 
landowners in Texas to reach agreements with them concerning 
maintenance of important habitat, the Service has determined that 
designation of critical habitat in Texas is unnecessary and would not 
be beneficial to the pygmy-owl. Furthermore, a probable outcome of such 
a designation in Texas would be an increase in disturbance to pygmy-
owls by bird watchers. An increase in bird watchers trespassing on 
private land is a concern expressed by private landowners, and such 
events could damage a currently harmonious working relationship with 
the Service and researchers.
    Section 4(b)(8) requires, for any proposed or final regulation that 
designates critical habitat, a brief description and evaluation of 
those activities (public or private) that may adversely modify such 
habitat or may be affected by such designation. Such activities may 
include:
    (1) Removing, thinning or destroying vegetation. Activities that 
remove, thin, or destroy vegetation, by mechanical (woodcutting or 
bulldozing), chemical (herbicides or burning), or biological (grazing) 
means;
    (2) Water diversion or impoundment, groundwater pumping, or any 
other activity that may significantly alter the quantity or quality of 
surface or subsurface water flow;
    (3) Overstocking or other mismanagement of livestock; and
    (4) Development of recreational facilities and off-road vehicle 
operation.
    Section 4(b)(2) of the Act requires the Service to consider 
economic and other impacts of designating a particular area as critical 
habitat. The Service will consider the critical habitat designation in 
light of all additional relevant information obtained before making a 
decision on whether to issue a final rule.

Special Rule

    The Service recognizes that the major portion of the population in 
Texas exists because present land management by private landowners is 
generally compatible with the well-being of the owl. The Service 
intends to work with landowners in developing management plans and 
agreements with the objective of recovery and eventual delisting of the 
Texas population. The Service is also proposing a special rule under 
section 4(d) of the Act that offers additional management flexibility 
for this species. The special rule would remove the prohibition against 
incidental taking of this species in any area subject to a conservation 
agreement between the Service and the landowner when the taking is 
caused by routine ranching activities and does not involve any 
destruction of nest trees. In order for a conservation agreement to be 
accepted by the Service, it would have to describe the activities to be 
undertaken in the area that may affect the species; estimate the amount 
extent, and type of incidental taking likely to result from these 
activities; and prescribe adequate mitigation measures.
    The Service believes that a special rule of this nature will 
benefit the cactus ferruginous pygmy-owl in Texas, and that the rule 
would satisfy the requirement under section 4(d) that regulations 
applied to threatened species embody those measures deemed necessary 
and advisable to provide for the conservation of the species in 
question.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing encourages and results in 
conservation actions by Federal, State, and private agencies, groups, 
and individuals. The Act provides for possible land acquisition and 
cooperation with the States and authorizes recovery plans for all 
listed species. The protection required for Federal agencies and the 
prohibitions against taking and harm are discussed, in part, below.
    Section 7(a) of the Act, as amended, requires Federal agencies to 
evaluate their actions with respect to any species that is proposed or 
listed as endangered or threatened and with respect to its critical 
habitat, if any is being designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
Part 402. Section 7(a)(4) requires Federal agencies to confer 
informally with the Service on any action that is likely to jeopardize 
the continued existence of a proposed species or result in destruction 
or adverse modification of proposed critical habitat. If a species is 
listed subsequently, Section 7(a)(2) requires Federal agencies to 
ensure that activities they authorize, fund, or carry out are not 
likely to jeopardize the continued existence of such a species or to 
destroy or adversely modify its critical habitat. If a Federal action 
may affect a listed species or its critical habitat, the responsible 
Federal agency must enter into formal consultation with the Service.
    The Act and implementing regulations found at 50 CFR 17.21 and 
17.31 set forth a series of general prohibitions and exceptions that 
apply to all endangered and threatened wildlife, respectively. These 
prohibitions, in part, make it illegal for any person subject to the 
jurisdiction of the U.S. to take (includes harass, harm, pursue, hunt, 
shoot, wound, kill, trap, or collect; or to attempt any of these), 
import or export, ship in interstate commerce in the course of 
commercial activity, or sell or offer for sale in interstate or foreign 
commerce any listed species. It also is illegal to possess, sell, 
deliver, carry, transport, or ship any such wildlife that has been 
taken illegally. Certain exceptions apply to agents of the Service and 
State conservation agencies.
    Permits may be issued to carry out otherwise prohibited activities 
involving endangered and threatened wildlife species under certain 
circumstances. Regulations governing permits are at 50 CFR 17.22, 
17.23, and 17.32. Such permits are available for scientific purposes, 
to enhance the propagation or survival of the species, and/or for 
incidental take in connection with otherwise lawful activities. For 
threatened species, there are also permits for zoological exhibition, 
educational purposes, or special purposes consistent with the purpose 
of the Act.
    Section 4(d) of the Act provides authority for the Service to 
promulgate special rules for threatened species. The Service is 
proposing a special rule for the cactus ferruginous pygmy-owl in Texas 
that would relax the prohibition against incidental taking where the 
Service and a landowner have entered into a conservation agreement.

Public Comments Solicited

    The Service intends that any final action resulting from this 
proposal will be as accurate and as effective as possible. Therefore, 
comments or suggestions from the public, other concerned governmental 
agencies, the scientific community, industry, or any other interested 
party concerning this proposed rule are hereby solicited. Comments 
particularly are sought concerning:
    (1) Biological, commercial trade, or other relevant data concerning 
any threat (or lack thereof) to this species;
    (2) The location of any additional populations of this species and 
the reasons why any habitat should or should not be determined to be 
critical habitat as provided by Section 4 of the Act;
    (3) Additional information concerning the range, distribution, and 
population size of this species;
    (4) Current or planned activities in the subject area and their 
possible impacts on this species; and
    (5) Any foreseeable economic and other impacts resulting from the 
proposed designation of critical habitat.
    Final promulgation of a regulation on this species will take into 
consideration the comments and any additional information received by 
the Service, and such communications may lead to a final regulation 
that differs from this proposal.
    The Endangered Species Act provides for a public hearing on this 
proposal, if requested. Requests must be received within 45 days of the 
date of publication of this proposal; such requests must be made in 
writing and addressed to the Service's Arizona State Office (see 
ADDRESSES section).

National Environmental Policy Act

    The Fish and Wildlife Service has determined that an Environmental 
Assessment, 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 the Service's 
reasons for this determination was published in the Federal Register on 
October 25, 1993 (48 FR 49244).

References Cited

    A complete list of all references cited herein is available from 
the Service's Arizona State Office (see ADDRESSES).

Author

    The primary author of this proposed rule is Robert M. Marshall, 
Arizona Ecological Services State Office (see ADDRESSES) above.

List of Subjects in 50 CFR Part 17

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

Proposed Regulation Promulgation

    Accordingly, the Service hereby proposes to amend part 17, 
subchapter B of chapter I, title 50 of the Code of Federal Regulations, 
as set forth below:

PART 17--[AMENDED]

    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; 16 U.S.C. 
4201-4245; Pub. L. 99-625, Stat. 3500; unless otherwise noted.

    2. Section 17.11(h) is amended by adding the following, in 
alphabetical order under Birds, to the list of Endangered and 
Threatened Wildlife, to read as follows:


Sec. 17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                         Species                                                         Vertebrate                                                     
----------------------------------------------------------                               population                                                     
                                                                                            where                                 Critical     Special  
                                                                  Historic range         endangered      Status    When listed    habitat       rules   
         Common name                Scientific name                                          or                                                         
                                                                                         threatened                                                     
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
                                                                      * * * * * * *                                                                     
            Birds                                                                                                                                       
                                                                                                                                                        
                                                                      * * * * * * *                                                                     
Pygmy-owl, cactus             Glaucidium brasilianum       U.S.A. (AZ, TX), Mexico....  AZ                      E  ...........     17.95(b)           NA
 ferruginous.                  cactorum.                                                                                                                
                                                                                                                                                        
                                                                                                                                                        
                                                                      * * * * * * *                                                                     
Do..........................  do.........................  do.........................  TX                      T  ...........           NA     17.41(c)
                                                                                                                                                        
                                                                                                                                                        
                                                                      * * * * * * *                                                                     
--------------------------------------------------------------------------------------------------------------------------------------------------------

    3. Section 17.41 is amended by adding paragraph (c) to read as 
follows:


Sec. 17.41  Special rules--birds.

* * * * *
    (c) Cactus ferruginous pygmy-owl (Glaucidium brasiliarum cactorum). 
(1) Except as noted in paragraph (c)(2) of this section, all 
prohibitions of Sec. 17.31 (a) and (b) shall apply to the cactus 
ferruginous pygmy-owl in Texas.
    (2) Incidental take of the cactus ferruginous pygmy-owl will not be 
a violation of section 9 of the Endangered Species Act of 1973, as 
amended, if it results from routine ranching operations, such as 
fencing and road building or maintenance, provided that:
    (i) No nest trees are destroyed.
    (ii) The owner of the land upon which the incidental take occurs 
and the Service have signed a conservation agreement that provides for 
the persistence of essential habitat features for the cactus 
ferruginous pygmy-owl. The conservation agreement must include, at 
minimum:
    (A) A description of activities that may affect the cactus 
ferruginous pygmy-owl.
    (B) An estimate of the amount, extent, and type of incidental 
taking that may result from these activities.
    (C) A description of any mitigation measures, such as seasonal 
restrictions or protection of nests groves, that will be carried out to 
minimize impact to and taking of cactus ferruginous pygmy-owls.
    (iii) The operations that may affect the cactus ferruginous pygmy-
owl are in compliance with all other Federal and State laws that 
provide protection for the cactus ferruginous pygmy-owl.
    4. Section 17.95(b) is amended by adding critical habitat of the 
cactus ferruginous pygmy-owl, in the same alphabetical order as the 
species occurs in Sec. 17.11(h), to read as follows:


Sec. 17.95  Critical habitat--Fish and wildlife.

* * * * *
    (b) * * *
* * * * *
Cactus Ferruginous Pygmy-Owl (Glaucidium brasilianum cactorum)
    Arizona. Areas of land and water as follows (all legal descriptions 
are from the Gila and Salt River Meridian):
    1. Maricopa County: Salt River, from Stewart Mountain Dam (T3N, 
R8E, Section 33) downstream to Granite Reef Dam (T2N, R7E, Section 5). 
The boundaries include the current active channel(s), and all 
secondary, side, and overflow channels, up to and including the 100-
year floodplain, and areas within 100 m (328 ft) laterally adjacent to 
the 100-year floodplain.
    2. Maricopa County: Verde River, from Bartlett Dam (T4N, R7E, 
Section 33) downstream to the confluence of the Verde and Salt Rivers 
(T2N, R7E, Section 5). The boundaries include the current active 
channel(s), and all secondary, side, and overflow channels, up to and 
including the 100-year floodplain, and areas within 100 m (328 ft) 
laterally adjacent to the 100 year-floodplain.
    3. Cochise, Pima, and Pinal Counties: San Pedro River, from the 
confluence of Soza Canyon (T12S, R19E, Section 30) downstream to the 
confluence of the San Pedro and Gila Rivers (T5S, R15E, Section 23), 
including Cook's Lake. The boundaries include the current active 
channel(s), and all secondary, side, and overflow channels, up to and 
including the 100-year floodplain, and areas within 100 meters (328 
feet) laterally adjacent to the 100-year floodplain.
    4. Pima County: Santa Cruz River, from the Interstate 19 bridge 
(T15S, R13E, Section 26) downstream to the Avra Valley Road bridge 
(T12S, R12E, Section 8). The boundaries include the current active 
channel(s), and all secondary, side, and overflow channels, up to and 
including the 100-year floodplain, and areas within 100 meters (328 ft) 
laterally adjacent to the 100-year floodplain.
    5. Pima County: Rillito Creek system, from the confluence of 
Rillito Creek and the Santa Cruz River (T13S, R13E, Section 7) 
upstream, along Tanque Verde Creek to the boundary between Sections 2 
and 3, T14S, R16E, and upstream along Agua Caliente Creek to the 
Soldier Trail crossing (T13S, R16E, Section 19). The boundaries include 
the current active channel(s), and all secondary, side, and overflow 
channels, up to and including the 100-year floodplain, and areas within 
100 m (328 ft) laterally adjacent to the 100-year floodplain.
    6. Pima County: Canada del Oro, from its confluence with Sutherland 
Wash (T11S, R14E, Section 4) downstream to its confluence with the 
Santa Cruz River (T13S, R12E, Section 1). The boundaries include the 
current active channel(s), and all secondary, side, and overflow 
channels, up to and including the 100-year floodplain, and areas within 
100 meters (328 feet) laterally adjacent to the 100-year floodplain.
    7. Pima County: Alamo/Growler Wash system, from the well in Alamo 
Canyon (T16S, R4W, unsurveyed Section 6) downstream to the point where 
Growler Wash intersects the Bates Well road (T15S, R7W, Section 6). The 
boundaries include the current active channel(s), and all secondary, 
side, and overflow channels, up to and including the 100-year 
floodplain, and areas within 100 m (328 ft) laterally adjacent to the 
100-year floodplain.
    8. Pima County: Arivaca Creek, from the road crossing in the town 
of Arivaca (T21S, R10E, Section 28) downstream to the confluence with 
San Luis Wash (T21S, R9E, Section 4). The boundaries include the 
current active channel(s), and all secondary, side, and overflow 
channels, up to and including the 100-year floodplain, and areas within 
100 m (328 ft) laterally adjacent to the 100-year floodplain.
    9. Greenlee and Graham Counties: Gila River, from the confluence 
with the San Francisco River (T5S, R29E, Section 28) downstream to the 
gaging station in Section 31, T6S, R28E. The boundaries include the 
current active channel(s), and all secondary, side, and overflow 
channels, up to and including the 100-year floodplain, and areas within 
100 m (328 ft) laterally adjacent to the 100-year floodplain.
    10. Pinal and Graham Counties: Gila River, from the confluence with 
the San Pedro River (T5S, R15E, Section 23) downstream to the Ashurst-
Hayden Dam (T4S, R11E, Section 8). The boundaries include the current 
active channel(s), and all secondary, side, and overflow channels, up 
to and including the 100-year floodplain, and areas within 100 m (328 
ft) laterally adjacent to the 100-year floodplain.
    11. Graham County: Bonita Creek, from the boundary between Section 
36 (T5S, R27E) and Section 31 (T5S, R28E) downstream to the confluence 
of Bonita Creek and the Gila River (T6S, R28E, Section 21). The 
boundaries include the current active channel(s), and all secondary, 
side, and overflow channels, up to and including the 100-year 
floodplain, and areas within 100 m (328 ft) laterally adjacent to the 
100-year floodplain.
    12. Maricopa County: New River, from the boundary between Sections 
3 and 4, Township 7 North, Range 3 East, downstream to the boundary 
between Sections 19 and 20, Township 6 North, Range 2 East. The 
boundaries include the current active channel(s), and all secondary, 
side, and overflow channels, up to and including the 100-year 
floodplain, and areas within 100 m (328 ft) laterally adjacent to the 
100-year floodplain.
    The primary constituent elements of cactus ferruginous pygmy owl 
critical habitat include: Sonoran Desertscrub, xeroriparian thickets, 
riparian thickets, forests, and woodlands, and areas where such 
vegetation does not currently exist but may become established with 
natural regeneration or habitat rehabilitation.

    Note: Map follows:

BILLING CODE 4310-55-M

TP12DE94.002

BILLING CODE 4310-55-C

    Dated: December 6, 1994.
George T. Frampton, Jr.,
Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 94-30468 Filed 12-7-94; 1:27 pm]
BILLING CODE 4310-55-M