# 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

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## Record

- **Collection:** Federal Register
- **Document type:** Uncategorized Document
- **Published:** December 12, 1994

## Text

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

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-30468. Public record. Not legal advice.