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RIN ID: RIN 1018-AV52
FWS ID: [FWS-R4-ES-2008-0047; 92210-1117-0000-FY08-B4]
SUBJECT CATEGORY: Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Louisiana Black Bear (Ursus americanus luteolus)
DOCUMENT SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to designate critical habitat for the Louisiana black bear under the Endangered Species Act of 1973, as amended (Act). Concurrently, we withdraw our December 2, 1993, proposal for Louisiana black bear critical habitat (58 FR 63560). In total, approximately 1,330,000 acres (538,894 hectares (ha)) fall within the boundaries of this proposed critical habitat designation. The proposed critical habitat is located in Avoyelles, East Carroll, Catahoula, Concordia, Franklin, Iberia, Iberville, Madison, Pointe Coupee, Richland, St. Martin, St. Mary, Tensas, West Carroll, and West Feliciana Parishes, Louisiana.
SUMMARY: Interior Department, Fish and Wildlife Service,
We intend that any final action resulting from this proposal will
be as accurate and as effective as possible. Therefore, we request
comments or suggestions on this proposed rule. We particularly seek comments concerning:
(1) The reasons why we should or should not designate habitat as
``critical habitat'' under section 4 of the Act (16 U.S.C. 1531 et
seq.), including whether there are threats to the species from human
activity, the degree of which can be expected to increase due to the
designation, and whether the benefit of designation would outweigh
threats to the species caused by the designation, such that the designation of critical habitat is prudent.
(2) Specific information on:
You may submit your comments and materials concerning this proposed rule by one of the methods listed in the ADDRESSES section. We will not consider comments sent by email or fax or to an address not listed in the ADDRESSES section.
If you submit a comment via http://www.regulations.gov, your entire commentincluding any personal identifying informationwill be posted on the Web site. If you submit a hardcopy comment that includes personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so. We will post all hardcopy comments on http://www.regulations.gov.
Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection on http://www.regulations.gov, or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Louisiana Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).
It is our intent to discuss only those topics directly relevant to the designation of critical habitat in this proposed rule. For more information on the threatened Louisiana black bear or its habitat, refer to the final listing rule published in the Federal Register on January 7, 1992 (57 FR 588), and to our 1995 final recovery plan, which is available online at http://www.regulations.gov or from the Louisiana Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).
This proposal replaces our original critical habitat proposal for
the Louisiana black bear published on December 2, 1993 (58 FR 63560).
In that rule, we proposed three critical habitat units encompassing
most of the Lower Mississippi River Valley in Louisiana: (1) Tensas
River Basin (1,671,782 ac (676,546 ha)), a small portion of which was
located in the State of Mississippi lying west of the Mississippi River
Main channel; (2) Atchafalaya Floodway (978,279 ac (395,895 ha)); and
(3) Lower IberiaSt. Mary Parish (364,770 ac (147,617 ha)). The total
area within the proposed boundary was approximately 3 million acres
(1,220,058 ha), of which approximately 1.25 million acres (505,857 ha)
were estimated to contain the essential physical and biological
features. There has been a significant amount of new information gathered
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about this subspecies and its habitat since 1993. We are therefore
withdrawing our original December 2, 1993, proposal to consider that
new information and to comply with a September 5, 2007, order from the
U.S. District Court for the Western District of Louisiana (see Previous Federal Actions section).
The Louisiana black bear is one of 16 subspecies of the American black bear (Ursus americanus). The black bear is a large, bulky mammal with long black hair and a short, wellhaired tail. The facial profile is blunt, the eyes small, and the nose pad broad with large nostrils. There are five toes with short, curved claws on the front and hind feet. Although weight varies considerably throughout their range, adult male black bears can weigh more than 600 pounds (lbs) (272 kilograms (kg)); adult females generally weigh less than 300 lbs (136 kg) (Pelton 1982, p. 504). The median estimated weights for male and female Louisiana black bears in north Louisiana were 292 lbs (133 kg) and 147 lbs (67 kg) respectively (Weaver 1999, p. 26).
Bear activity revolves primarily around the search for food, water, cover, and mates during the breeding season. Bears are best described as opportunistic feeders, as they eat almost anything that is available; thus, they are typically omnivorous (Pelton 1982, p. 504). Their diet varies seasonally and includes primarily succulent vegetation during spring, fruits and grains in summer, and hard mast (such as acorns and pecans) during fall (Weaver 1999, pp. 149, 157). Black bears utilize all levels of the forest for feeding; they can gather foods from tree tops and vines, but also grub in fallen logs for insects. The growth rate, maximum size, breeding age, litter size, and cub survival of black bears are all correlated with nutrition (Black Bear Conservation Committee (BBCC) 1997, p. 17).
Home range sizes vary annually and seasonally (BBCC 2005, p. 11) and home range configuration appears to be influenced by available forest cover (Marchinton 1995, p. 48). Black bears do not truly hibernate, but go through a dormancy period termed ``carnivoran lethargy,'' which is a period of torpor which helps them survive food shortages and severe weather during the winter. In warmer climates, such as in Louisiana, bears can remain active all winter (Wagner 1995, pp. 2425). Bears den in heavy cover or tree cavities during the winter months (Weaver 1999, p. 118) and den type may vary depending on the habitat. Cubs are born in winter dens at the end of January or the beginning of February (Weaver 1990, p. 5). Bears may enter dens between November and early January depending on latitude, available food, sex, age, and local weather conditions (Weaver 1990, p. 6). Adult females generally enter the den first, followed by subadults and adult males. At the end of the dormancy period, females with cubs are usually the last to leave the den. Adult male bears generally have home ranges 3 to 8 times larger than adult females (Pelton 1982, p. 507) and have been observed to travel up to 35 miles (mi) (56 kilometers (km)) from their capture site (BBCC 2005, p. 11). Changes in food resources can provide the stimulus for extensive movements (Pelton 1982, p. 507). Additionally, older adult males exert social pressure on younger bears, especially during the spring and summer breeding season, forcing them to disperse to other areas (Pelton 1982, p. 507).
Like other black bears, the Louisiana black bear is a habitat generalist. Large tracts of bottomland hardwood (BLH) forest communities having high species and age class diversity can provide for the black bear's life requisites (e.g., escape cover, denning sites, and hard and soft mast supplies) without intensive management (BBCC 2005, p. 21). We use the term BLH forest community with no particular inference to hydrologic influence; we use this term to mean forests within southeastern United States floodplains which can consist of a number of woody species occupying positions of dominance and co dominance (BBCC 1997, p. 15). Other habitat types may be utilized, including marsh; upland forested areas; forested spoil areas along bayous, brackish marsh, and freshwater marsh; salt domes; and agricultural fields (Nyland 1995, p. 48; Weaver 1999, p. 157). Large cavity trees (especially cypress or tupelo gum) that are commonly found along water courses are important for denning.
The Louisiana black bear was once a common inhabitant of forested areas in east Texas, Louisiana, and southern Mississippi (BBCC 1997, p. 10). Bear densities were likely highest within BLH and oakhickory forest communities where hard mast production was greater than in other habitats (BBCC 1997, p. 12). While Hall included the southernmost counties in Arkansas as part of the historic range (1981, p. 950), there were no data to support doing so at the time of listing; accordingly, Arkansas is not considered part of the listed range (January 7, 1992; 57 FR 588).
The Louisiana black bear was listed as threatened under the Act on January 7, 1992 (57 FR 588), due to extensive habitat loss and modification, as well as the ongoing threats of continued habitat modification and humanrelated mortality. More than 80 percent of suitable Louisiana black bear habitat had been lost by the time of listing (1992) primarily due to clearing land for agriculture (Weaver 1990, p. 1); the remaining habitat quality had been reduced by fragmentation and human activities. At that time, Louisiana black bears were generally known to occur in the Lower Mississippi River Alluvial Valley BLH forest communities of the Tensas River Basin of northeastern Louisiana and the Atchafalaya River Basin in central and southern Louisiana (Weaver 1990, p. 2; BBCC, 1997, p. 12); however, occupied habitat had not been definitively delineated. Those forest communities were likely sites for population persistence due to their remoteness and habitat productivity (BBCC 1997, p. 13). All known breeding populations were believed to be demographically isolated at the time of listing (BBCC 1997, p. 10). Bears had been occasionally reported in Louisiana outside of these areas, but it was unknown if those bears were reproducing females or only wandering subadults and adult males. Black bears were also known to exist in Mississippi along the Mississippi River (Weaver 1990, p. 2) and smaller areas in the lower East Pearl River and lower Pascagoula River basins of southern Mississippi (Weaver 1990, p. 2). The last native breeding group in Mississippi was last documented about 1980 (Nowak 1986, p. 7). Except for wanderers, the bear has not appeared in eastern Texas for many years (Nowak 1986, p. 7).
We use the term ``breeding habitat'' for the Louisiana black bear
to indicate areas with physical evidence of reproduction (young,
females with young, or lactating females). Louisiana black bear
resource managers and biologists commonly refer to such areas as
occupied habitat (USFWS 1995, p. 2; BBCC 1997, p. 72); however, we will
use the term ``occupied habitat'' to indicate the subspecies' presence
in an area at the time of listing. In contrast to sightings of adults
without reproductive information, reproduction is considered evidence
of a resident bear population. Dispersal by female black bears is
uncommon and typically is of a short distance (Rogers 1987, p. 43).
Male black bear home ranges usually encompass several female home
ranges (Rogers 1987, p. 19). For instance, in the Tensas population,
most male Louisiana black bear home ranges (95 percent minimum convex polygon (MCP)) were observed to include numerous female
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home ranges (Weaver 1999, p. 74 and p. 308, Figure E5). Therefore,
while breeding habitat does not necessarily include all areas where
individual bears may occur, it does encompass the areas known to
support resident, reproducing populations. Clark et al. (2005, p. 246)
used a similar method to update black bear distribution maps for the
southeastern United States. Clark (1999, p. 105) states researchers and
managers should focus on the population parameters of greatest
consequence to population growth. Adult female survival is the most
influential factor affecting black bear population growth (Clark 1999,
pp. 103105). Hellgren and Vaughan (1994, p. 283) conclude that managed
female survival is a critical conservation need. The Black Bear
Conservation Committee's (BBCC) restoration plan identified breeding
habitats (as defined above) as those areas where essential management
and restoration activities for the Louisiana black bear must be focused (BBCC 1997, p. 4).
Currently, Louisiana black bear breeding populations are predominantly restricted to three disjunct core (concentrated) populations, the Tensas, and the Upper Atchafalaya, and the Lower Atchafalaya River Basins, Louisiana. A fourth additional, newly forming, repatriation core population occurs in eastcentral Louisiana, in the vicinity of the Red River and Three Rivers Wildlife Management Areas (WMA), and Lake Ophelia National Wildlife Refuge (NWR). The Tensas River Basin (Tensas) breeding population occurs on a complex of BLH forests comprised of Tensas River NWR, adjacent Big Lake WMA, and four nearby small, relatively isolated, forested tracts formerly owned by Deltic Timber Corporation (now owned by Epps Plantation) in Tensas, Madison, Franklin, East Carroll, and Richland Parishes in Louisiana. The Deltic tracts support one of the highest densities of black bears reported for the southeastern coastal plain (Beausoleil 1999, p. 80). The Deltic tracts are approximately 14 mi (23.5 km) north of the Tensas River NWR; their closest areas are separated by only 2.5 mi (4 km) and by U.S. Interstate 20 (I20). Historically, Louisiana black bears inhabiting the Tensas River NWR group have generally been considered a separate group of bears from those inhabiting the Deltic tracts. Only one instance of a bear moving between these two areas has been documented (Anderson 1997, p. 70). Though the two subgroups are separated by I20 and U.S. Highway 80, a significant amount of habitat between those subgroups has been restored primarily within the last 10 years. Increased sightings and vehicular mortality of bears in the vicinity of I20 indicate that bears are attempting to disperse (Benson 2005, p. 97). The 6 bear mortalities documented on I20 in 2004 and the continuing regular occurrence of mortalities, versus the total of 5 mortalities in the previous 10 years indicate that bears are moving between these previously isolated populations (LDWF 2007, p. 20) and that the two subgroups have likely begun to function as one population.
Two Louisiana black bear populations are located in the Atchafalaya River Basin (BBCC 1997, p. 10). The Upper Atchafalaya River Basin population (Upper Atchafalaya) is located primarily within the Morganza Floodway and the forested areas between that Floodway and False River in Pointe Coupee Parish in Louisiana, and is approximately 110 mi (177 km) south of the Tensas population. Much of the land between these two populations has been cleared for agricultural use. The Lower Atchafalaya River Basin population (Lower Atchafalaya) is found primarily south of U.S. Highway 90 (Hwy. 90) and west of the lower Atchafalaya River and Delta, in the coastal area of St. Mary and Iberia Parishes. It is located approximately 70 mi (113 km) south of the Upper Atchafalaya population and is separated from that population by U.S. Interstate 10, Hwy. 90, the Atchafalaya River, Bayou Teche, agricultural lands, developed areas, and permanently and seasonally inundated portions of the Atchafalaya River Basin, which is not currently believed to contain breeding bears due to the flooding regime. Population expansion in the coastal area is limited by development along Hwy. 90 to the north, and by the surrounding coastal marsh, which is believed to be unsuitable for sustaining bear populations.
A fourth breeding population has been recently established in Avoyelles and Concordia Parishes, Louisiana, near the confluence of the Mississippi and Red Rivers, an area containing approximately 100,000 ac (40,469 ha) of publicly owned, forested land. This area is separated from the Tensas and the Upper Atchafalaya populations primarily by agricultural lands. As the result of a multiagency repatriation project, 36 adult females and 82 cubs have been relocated to public lands in this area between 2001 and 2007, to reduce demographic isolation of existing populations (LDWF 2007, p. 15). This project was developed on the assumption that relocated females would remain at the new location and would be discovered by males traveling through the area. Natural reproduction of those bears was first documented in 2005, and reproduction has since been documented in 5 litters (LDWF 2006, p. 1), resulting in an additional breeding population in Louisiana.
Louisiana black bear reproduction was speculated to occur in Mississippi at the time of listing (1992) (Stinson 1996, p. 15), but was not confirmed until 2005 when a radiocollared female, moved as part of a reintroduction project in Louisiana, crossed into Mississippi and had cubs (Telesco 2006, p. 12). Breeding has been subsequently documented for several additional individuals, but to date no core breeding populations are known to exist, and it is generally believed that the majority of bears in Mississippi are males that have dispersed from populations in other States (Young 2006, p. 14). The Texas Parks and Wildlife Department has also documented black bear sightings in eastern Texas in the last 7 years, though there are currently no known Louisiana black bear breeding populations in eastern Texas (TPWD 2005, p. 3). It is probable that most of those bears are juvenile or subadult males that have roamed into the area from expanding bear populations in Arkansas and Oklahoma (TPWD 2005, p. 7). Clark et al. (2005, p. 250, Figure 1) indicated the presence of a small breeding population with a few individuals crossing between Louisiana and Arkansas. This is likely the result of a black bear reintroduction project in Arkansas where female bears, reintroduced onto Felsenthal National Wildlife Refuge in Arkansas, have moved south into Louisiana (LDWF 2007, p. 1).
In 1997, the Statewide Louisiana black bear population was
estimated to range from 200 to 400 bears (Pelton and Van Manen 1997, p.
38). No reliable overall Louisiana black bear population estimate
currently exists; however, estimates have been developed for specific
geographic areas. Estimates for the Tensas River NWR population range
from 119 to 131 bears (Boerson et al. 2003, p. 203) and, for the nearby
Deltic tracts, from 34 to 47 bears (Beausoleil 1999, p. 51). The Upper
Atchafalaya population was estimated to range from 68 to 86 bears and,
for the Lower Atchafalaya, from 28 to 47 bears (Triant et al. 2004, p.
653), but these may be underestimates of the actual population numbers
(Triant et al. 2004, p. 655). There are no population estimates for the
repatriation population; however, a total of 36 females and 82 cubs
have been moved to this area. Most studies of the Louisiana black bear have been
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conducted in these core breeding habitat areas and therefore probably
small, but unknown, numbers of bears occurring outside those areas are
not included in population estimates. Population estimates for
Louisiana black bears at the time of listing appear to be lower than
what recent research would indicate, and there is circumstantial
evidence that the population is growing (LDWF 2007, p. 22). Previous Federal Actions
We listed the Louisiana black bear (Ursus americanus luteolus) as threatened under the Act on January 7, 1992 (57 FR 588). Other free living bears of the species U. americanus within the same range specified in that rule were designated as threatened by similarity of appearance. In our final rule listing this subspecies, we determined that normal forest management activities supporting a sustained yield of timber products and wildlife habitats were compatible with Louisiana black bear's needs. Accordingly, we promulgated a special rule at 50 CFR 17.40(i) exempting the effects incidental to normal forest management activities within the subspecies' historic range, except for activities causing damage to or loss of den trees, den tree sites, or candidate den trees (57 FR 588). For the purposes of that exemption, normal forest management activities were those activities that support a sustained yield of timber products and wildlife habitats, thereby maintaining forestland conditions in occupied (i.e., breeding) habitat. Research has supported this decision. In fact, in some cases, such as leaving downed tree tops and creating openings, timber management can provide or enhance black bear habitat (Weaver 1999, pp. 126128; Hightower et al. 2002, p. 14; Weaver et al. 1990, p. 344; Lindsey and Meslow 1977, p. 424). Therefore, we do not propose changing the special rule at 50 CFR 17.40(i) as part of the critical habitat designation.
Designation of critical habitat was found to be not determinable at the time of listing. We proposed critical habitat for the Louisiana black bear on December 2, 1993 (58 FR 63560). That proposal had a 90 day comment period, ending March 2, 1994. We then reopened the public comment period from March 7, 1994 (59 FR 10607) through April 4, 1994. During that reopened comment period, we held a public hearing in New Iberia, Louisiana, on March 23, 1994. On April 1, 1994, we extended the reopened comment period through May 25, 1994, and announced two more public hearings (May 10, 1994, in West Monroe, Louisiana, and May 11, 1994, New Iberia, Louisiana) (59 FR 15366). We never published a final rule designating critical habitat. On September 6, 2005, Mr. Harold Schoeffler and Louisiana Crawfish Producers AssociationWest filed suit in U.S. District Court for the Western District of Louisiana (Civil Action No. CV051573 (W.D. La.)) regarding the Service's failure to designate critical habitat for the Louisiana black bear.
On June 25, 2007, the District Court ordered the Service to withdraw the December 2, 1993, proposed critical habitat rule and create a new proposed critical habitat designation by no later than 4 months from the date of the judgment and to publish a final designation by no later than 8 months from the date of the proposed or new rule. On September 5, 2007, following a settlement agreement, the Court revised its order to require the Service to: (1) Withdraw the December 2, 1993, proposed rule and submit a prudency determination and, if prudent, a new proposed critical habitat designation to the Federal Register by April 26, 2008; and (2) submit a final critical habitat determination, if applicable, to the Federal Register by February 26, 2009. This publication is: (1) Our withdrawal of the 1993 proposal; (2) our new prudency determination; and (3) our proposed rule to designate critical habitat for the Louisiana black bear in accordance with section 4(b)(2) of the Act. For more information on previous Federal actions concerning the Louisiana black bear, refer to the proposed critical habitat rule published on December 2, 1993 (58 FR 63560).
Critical habitat is defined in section 3(5)(A) of the Act as:
(1) 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
(a) Essential to the conservation of the species and
(b) Which may require special management considerations or protection; and
(2) 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.
Conservation, as defined under section 3 of the Act, means the use of all methods and procedures that are necessary to bring any endangered species or threatened species to the point at which the measures provided under the Act are no longer necessary.
Critical habitat receives protection under section 7 of the Act through the prohibition against Federal agencies carrying out, funding, or authorizing the destruction or adverse modification of critical habitat. Section 7 of the Act requires consultation on Federal actions that may affect critical habitat. The designation of critical habitat does not affect land ownership or establish a refuge, wilderness, reserve, preserve, or other conservation area. Such designation does not allow the government or public to access private lands. Such designation does not require implementation of restoration, recovery, or enhancement measures by the landowner. Where the landowner seeks or requests Federal agency funding or authorization that may affect a listed species or critical habitat, the consultation requirements of section 7 of the Act would apply, but even in the event of a destruction or adverse modification finding, the landowner's obligation is not to restore or recover the species, but to implement reasonable and prudent alternatives to avoid destruction or adverse modification of critical habitat.
For inclusion in a critical habitat designation, habitat within the geographical area occupied by the species at the time it was listed must contain features that are essential to the conservation of the species. Critical habitat designations identify, to the extent known using the best scientific data available, habitat areas that provide essential life cycle needs of the species (areas on which are found the primary constituent elements, as defined at 50 CFR 424.12(b)).
Occupied habitat that contains the features essential to the conservation of the species meets the definition of critical habitat only if those features may require special management considerations or protection.
Under the Act, we can designate unoccupied areas as critical habitat only when we determine that the best available scientific data demonstrate that the designation of that area is essential to the conservation needs of the species.
Section 4 of the Act requires that we designate critical habitat on
the basis of the best scientific and commercial data available.
Further, our Policy on Information Standards Under the Endangered
Species Act (published in the Federal Register on July 1, 1994 (59 FR
34271)), the Information Quality Act (section 515 of the Treasury and
General Government Appropriations Act for Fiscal Year 2001 (Pub. L.
106554; H.R. 5658)), and our associated Information Quality Guidelines provide criteria,
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establish procedures, and provide guidance to ensure that our decisions
represent the best scientific data available. They require our
biologists, to the extent consistent with the Act and with the use of
the best scientific data available, to use primary and original sources
of information as the basis for recommendations to designate critical habitat.
When we are determining which areas should be proposed as critical habitat, our primary source of information is generally the information developed during the listing process for the species. Additional information sources may include the recovery plan for the species, articles in peerreviewed journals, conservation plans developed by States and counties, scientific status surveys and studies, biological assessments, or other unpublished materials and expert opinion or personal knowledge.
Habitat is often dynamic, and species may move from one area to another over time. Furthermore, we recognize that designation of critical habitat may not include all of the habitat areas that we may eventually determine, based on scientific data not now available to the Service, are necessary for the recovery of the species. For these reasons, a critical habitat designation does not signal that habitat outside the designated area is unimportant or may not be required for recovery of the species.
Areas that support populations, but are outside the critical habitat designation, will continue to be subject to conservation actions we implement under section 7(a)(1) of the Act and our other wildlife authorities. They are also subject to the regulatory protections afforded by the section 7(a)(2) jeopardy standard, as determined on the basis of the best available scientific information at the time of the agency action. Federally funded or permitted projects affecting listed species outside their designated critical habitat areas may result in jeopardy findings in some cases. Similarly, critical habitat designations made on the basis of the best available information at the time of designation will not control the direction and substance of future recovery plans, habitat conservation plans (HCPs), or other species conservation planning efforts if new information available to these planning efforts calls for a different outcome.
Section 4(a)(3) of the Act and its implementing regulations (50 CFR 424.12) require that, to the maximum extent prudent and determinable, we designate critical habitat at the time a species is listed as endangered or threatened. Our regulations at 50 CFR 424.12(a)(1) state that the designation of critical habitat is not prudent when one or both of the following situations exist: (1) The species is threatened by taking or other activity and the identification of critical habitat can be expected to increase the degree of threat to the species; or (2) the designation of critical habitat would not be beneficial to the species. In our January 7, 1992, final rule (57 FR 588) we determined that designating critical habitat may be prudent, but was not determinable at that time. We subsequently proposed critical habitat for the Louisiana black bear on December 2, 1993 (58 FR 63560); however, we did not explicitly state in our proposed rule that such designation was prudent.
The Louisiana black bear was listed as threatened under the Act on January 7, 1992 (57 FR 588), due to extensive habitat loss and modification, and the ongoing threats of continued habitat modification and humanrelated mortality. The majority of area lands within the Louisiana black bear's historic range are privately owned. Some of those lands remain forested; however, most have been cleared for other uses such as agriculture. Conservation of the Louisiana black bear will require habitat protection and restoration and, therefore, is dependent upon the voluntary protection and restoration of privately owned lands.
Significant progress has been made in habitat restoration for the Louisiana black bear. Habitat and management actions voluntarily taken by private landowners are one important component of those restoration activities. Over 55,000 ac (22,250 ha) of private lands have been enrolled in the Natural Resource Conservation Service's Wetland Reserve Program (WRP) which has benefited Louisiana black bear conservation since 1992. WRP provides an incentive for private landowners to convert nonproductive farmland back to bottomland hardwoods, and many of these lands received higher rankings (when evaluated for enrollment) because of their benefit to Louisiana black bear conservation. Landowners enrolling in the WRP sign permanent easements protecting the restored land from future conversion or development. Designation of critical habitat on private lands may significantly reduce the likelihood that landowners will support and carry out conservation actions. Many landowners fear a decline in their property value due to real or perceived restrictions on landuse options where threatened or endangered species are found. Consequently, harboring endangered species is viewed by many landowners as a liability. This perception results in anticonservation incentives, because maintaining habitats that harbor endangered species represents a risk to future economic opportunities. This response was observed during the 19931994 Louisiana black bear critical habitat proposal process, when the majority of comments received were in opposition to designation, and several landowners who had previously allowed black bear research activities on their lands subsequently denied access to researchers and agency personnel.
Thus, there is potential, as a result of critical habitat designation, for a decline in WRP enrollment within Louisiana black bear habitat and restricted access to private lands for research; however, we will continue to work with Federal and State agencies, private organizations, and individuals in carrying out conservation activities for the Louisiana black bear, including habitat restoration, population surveys, and population restoration. Furthermore, the identification of areas that are necessary to ensure the conservation of the species is beneficial and critical habitat designation may provide additional information to individuals, local and State governments, and other entities engaged in longrange planning, since areas with features essential to the conservation of the species are clearly delineated and, to the extent currently feasible, the physical and biological features of the habitat necessary to the survival of this subspecies are specifically identified. This process is valuable to land owners and managers in developing conservation management plans for identified areas, as well as any other occupied habitat or suitable habitat that may not have been included in the Service's designation of critical habitat.
The additional threat, identified in the final rule listing the subspecies (57 FR 588), of illegal killing of Louisiana black bears remains an ongoing threat; however, such takings are believed to be opportunistic or in response to black bear nuisance activities. In the case of large mammals, such as the Louisiana black bear, population locations are already generally known and we do not expect identification of critical habitat to increase the degree of this threat.
Accordingly, we determine that designation of critical habitat will
not increase the degree of threat to the species and will be beneficial
for the Louisiana black bear; therefore, we determine that designation of critical habitat is prudent for this subspecies. At
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this time, we have sufficient information necessary to identify
specific areas that meet the definition of critical habitat and as
such, believe the critical habitat is also determinable. Therefore, we
are proposing critical habitat for the Louisiana black bear. Methods
As required by section 4(b) of the Act, we used the best scientific data available in determining areas occupied at the time of listing that contain features essential to the conservation of the Louisiana black bear, and areas unoccupied at the time of listing that are essential for the conservation of the Louisiana black bear, or both. We are not currently proposing any areas outside the geographical area presently occupied by the subspecies because the occupied areas being proposed are sufficient for the conservation of the subspecies.
We have also reviewed available information that pertains to the habitat requirements of this subspecies. After reviewing pertinent material, we consider it likely that the Louisiana subspecies is not significantly different from other black bears, because it is a habitat generalist. Material reviewed for the development of this critical habitat proposal included information from the January 7, 1992 (57 FR 588), final rule listing the Louisiana black bear as threatened; the December 2, 1993 (58 FR 63560) proposed rule to designate critical habitat; information and survey observations published in peerreviewed literature, academic theses, and agency reports; location data and survey information provided in agency reports and maps; habitat analyses and other information provided in the 1995 Louisiana Black Bear Recovery Plan and the complementary BBCC Black Bear Restoration Plan (1997); and material submitted during consultations under section 7 of the Act.
The following geospatial and tabular data sets were used in preparing this proposed critical habitat: Occurrence data for the Louisiana black bear (Louisiana Department of Wildlife and Fisheries, the U.S. Fish and Wildlife Service, Louisiana State University, and the University of Tennessee); 1998, 2004, and 2005 that is 1:24,000 digital raster and digital orthophoto quarterquadrangles (DOQQ); and 1:24,000 scale digital raster graphics (DRG) of the U.S. Geological Survey (USGS) topographic quadrangles. Habitat data was determined from the 2001 grid (raster) National Land Cover Dataset (NLCD) developed by The MultiResolution Land Characteristics (MRLC) Consortium. The MRLC is a group of Federal agencies who develop datasets used to track regional and global changes in land cover and land use, including such essential categories as forest and grassland cover. The MRLC consortium is specifically designed to meet the current needs of Federal agencies for nationally consistent satellite remote sensing and landcover data. We transformed the digital raster data to a vector format in order to obtain the most accurate area estimates of critical habitat when overlaid onto the critical habitat boundaries of lands containing features essential to the conservation of the subspecies. Land ownership was determined from geospatial data sets developed by the Service's Southeast Region Realty Division and the Louisiana State Lands Office.
We obtained additional information through personal communications with biologists, scientists, and land managers familiar with the Louisiana black bear and its habitat, including individuals affiliated with the Louisiana Department of Wildlife and Fisheries (LDWF), the Service, the BBCC, Louisiana State University, and the University of Tennessee. Specific information from these sources included estimates of historic and current distribution, abundance, and home range sizes, as well as data on resources and habitat requirements.
To delineate areas currently used by breeding populations, we acquired all available raw telemetry data (i.e., telemetry points) from those abovereferenced sources (recognizing the geographic limits of existing data in that they were collected from areas within known Louisiana black bear populations). Those telemetry points were buffered with average adult female home range sizes (as determined from published research) and were coalesced into polygons for each Louisiana black bear population. Those polygons were further refined based on habitat presence (as determined from DOQQs), contiguity of suitable habitat, proximity to noncontiguous suitable habitat, direct evidence of bear use, habitat patch size, and significant landscape features. We determined proposed critical habitat to be all areas within those polygons, except for those tracts that do not contain the physical and biological features essential to the conservation of the subspecies. We used telemetry data (where available), and DOQQs and DRGs to delineate habitat corridors. Areas proposed as critical habitat include areas that contain the physical and biological features essential to the conservation of the subspecies and either: (1) Currently support a breeding population of Louisiana black bears; or (2) function as corridors to maintain movement between core populations.
In accordance with section 3(5)(A)(i) of the Act and the
regulations at 50 CFR 424.12, in determining which areas occupied at
the time of listing to propose as critical habitat, we consider the
physical and biological features (PBFs) that are essential to the
conservation of the species to be the specific primary constituent
elements (PCEs) laid out in the appropriate quantity and spatial
arrangement for the conservation of the species. These include, but are not limited to:
(1) Space for individual and population growth and for normal behavior;
(2) Food, water, air, light, minerals, or other nutritional or physiological requirements;
(3) Cover or shelter;
(4) Sites for breeding, reproduction, or rearing (or development) of offspring; and
(5) Habitats that are protected from disturbance or are
representative of the historic, geographical, and ecological distributions of a species.
We derive the specific primary constituent elements (PCEs) for the Louisiana black bear from its biological needs.
Space for Individual and Population Growth and Normal Behavior
Louisiana black bear populations are currently found in the BLH
forest communities and associated habitat of the Lower Mississippi
River Alluvial Valley. Prime black bear habitat is characterized by
relatively inaccessible terrain, thick understory vegetation, and
abundant food sources in the forms of shrubs or treeborne soft or hard
mast (Pelton 1982, p. 507). BLH forest community types in the range of
the Louisiana black bear, expressed in terms of dominancecodominance,
include Taxodium distichum (bald cypress); T. distichumNyssa aquatica
(bald cypresswater tupelo); Betula nigraPlatanus occidentalis (river
birchAmerican sycamore); Populus deltoides (cottonwood); Celtis
laevigataUlmus americanaFraxinus pennsylvanica (sugarberryAmerican
elmgreen ash); Quercus nuttalliiU. americanaF. pennsylvanica
(Nuttall oakAmerican elmgreen ash); Q.lyrataCarya aquatica (overcup
oakwater hickory) Liquidambar styracifluaQ. nigra (sweetgumwater
oak); and Q. michauxiiQ. falcata (swamp chestnut oakcherrybark oak) (BBCC 1997, p. 15).
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Benson (2005, p. 56, Table 4.1) described habitat types in terms of
species, flooding regime, and age as: (1) Upland forestsBLH forests
in relatively high elevation sites not subject to frequent flooding;
and (2) lowland forestBLH forests in relatively low elevations
subject to seasonal or annual flooding. Louisiana black bear habitat in
the Lower Atchafalaya population differs from the Tensas and Upper
Atchafalaya areas in that it includes, in addition to forested wetlands
(e.g., deciduous forests, cypress forests, deciduous and bald cypress
forests, shrubscrub marshes), open marshes, deciduous forest spoil
banks, and upland hardwood forest (Nyland 1995, p. 58). The
interspersion of these communities may be important in meeting the
seasonal needs of the Lower Atchafalaya Louisiana black bear population
(Nyland 1995, p. 58). The coastal (or wetland) habitats may provide
escape cover, food sources, and secure travel corridors between other habitat types (Jones and Pelton 2003, p. 193).
The minimum size of an area necessary for black bears may differ depending on density, habitat quality, conservation goals, and assumptions regarding minimum viable populations (Rudis and Tansey 1995, p. 172). For example, Rudis and Tansey (1995, p. 172), citing personal communications, reported estimates of minimal areas needed to support a black bear population ranging from 79,000 ac (32,000 ha) in forested wetlands to 80,000 ac (197,700 ha) in upland forests. Cox et al. (1994, p. 50) estimated that a population of 200 or more bears could require a habitat base of approximately 490,000 to 980,000 ac (198,000 to 397,000 ha). Maintaining and enhancing key habitat patches within breeding habitat is a critical conservation strategy for black bears (Hellgren and Vaughan 1994, p. 276). Areas should be large enough to maintain female survival rates above the minimum rate necessary to sustain a population (Hellgren and Vaughan 1994, p. 280). Weaver (1999, pp. 105106) documented that bear home ranges and movements were centered in forested habitat and noted that actions to conserve, enhance, and restore that habitat would promote population recovery, although no recommendations on minimum requirements were provided. Hellgren and Vaughn (1994, p. 283) concluded that large, contiguous forests are a critical conservation need for black bears.
One approach to assess Louisiana black bear habitat needs is to look at existing densities; however, density estimates should be used with caution as they can be influenced by population estimation methodology and study area delineation. No single areadensity relationship has been developed for Louisiana black bears; however, density estimates have been developed for Louisiana black bears in two locations. Bear density for the Tensas River NWR subgroup was estimated to be 1 bear per 686 ac (0.36 per km\2\). This is low compared to other southeastern populations and to the adjacent Deltic subgroup with a density of 1 bear per 173 ac (1.43 per km\2\) (Boersen et al. 2003, p. 204). The unusually high densities observed on the Deltic tracts may be the result of the small size of the habitat fragments and accessibility to adjacent desirable agricultural crops (Boersen et al. 2003, p. 204).
Another approach to assess Louisiana black bear habitat requirements is to examine bear movements and home ranges. The home ranges of Louisiana black bears appear to be closely linked to forest cover (Marchinton 1995, p. 48). Female range size may be partly determined by habitat quality (Amstrup and Beecham 1976, p. 345), while male home range size may be determined by efficient monitoring of a maximum number of females (Rogers 1987, p. 19). Male black bears commonly disperse, and adult male bears can be wideranging with home ranges generally three to eight times larger than adult females (Pelton 1982, p. 507) and that may encompass several female home ranges (Rogers 1987, p. 19). Dispersal by female black bears is uncommon and typically is a short distance (Rogers 1987, p. 43). Females without cubs generally had larger home ranges than females with newborn cubs (Benson 2005, p. 46), although this difference was observed to vary seasonally, with movements more restricted in the spring (Weaver 1999, p. 99). Following separation of the mother and yearling offspring, young female black bears commonly establish a home range partially within or adjacent to their mother's home range (Rogers 1987, p. 39). Young males, however, generally disperse from their maternal home range. Limited information suggests that subadult males may disperse up to 124 mi (200 km) (BBCC 1997, p. 22).
Home range estimates vary for the Louisiana black bear. Mean median MCP home range estimates for the Tensas River NWR population were 35,736 ac (14,462 ha) and 5,550 ac (2,426 ha) for males and females, respectively (Weaver 1999, p. 70). Male home ranges (MCP) in the Upper Atchafalaya population may be as high as 80,000 ac (32,375 ha), while female home ranges are approximately 8,000 ac (3,237 ha) (Wagner 1995, p. 12). Lower Atchafalaya population home ranges (MCP) were estimated to be 10,477 ac (4,200 ha) for males, and 3,781 ac (1,530 ha) for females (Wagner 1995, p. 12). The smaller home ranges of Lower Atchafalaya bears when compared to Upper Atchafalaya bears may be due to superior habitat quality in the coastal area (Wagner 1995, p. 25). Louisiana black bears located on the Deltic lands in the Tensas River population have very small home ranges compared to other black bear populations with an estimated average home range (MCP) for males of 1,729 ac (700 ha) and for females 1,038 ac (420 ha) (Beausoleil 1999, p. 57). The smaller home ranges for this population are believed to be a result of the bears' reliance on the surrounding agricultural crops for forage (Benson 2005, p. 95) and the overall higher quality of the forested habitat (Weaver 1999, pp. 9091). Based on observations of the Deltic populations, Benson (2005, p. 95) suggested that it may be possible for a relatively large number of bears to require less space and persist in limited forest habitat if food is sufficiently abundant and diverse.
Habitat loss, besides reducing the overall area, can result in
fragmentation or isolation of habitat, as is evident for the Louisiana
black bear (Clark 1999, p. 107). Habitat fragmentation can restrict
bear movements both within and between populations (BBCC 1997, p. 23).
This can result in increased mortality as bears are forced to forage on
less protected sites, travel farther to forage, or cross barriers such
as roads (Pelton 1982, p. 507; Hellgren and Maehr 1992, pp. 154, 155,
156). Open areas, roads, large waterways, development, and large
expanses of agricultural land may affect habitat contiguity. Such
features tend to impede the movement of bears (Clark 1999, p. 107).
Habitat fragmentation also limits the potential for the present
Louisiana black bear population to expand its current breeding range
(USFWS 1995, p. 8). Habitat fragmentation can create barriers to
immigration and emigration that can affect population demographics and
genetic integrity (Clark et al. 2006, p. 12). Bear populations in a
relatively large habitat patch are not ensured of longterm survival
without recolonization by bears from adjacent patches (Clark 1999, p.
111). The long term protection of habitat and interconnecting corridors
or habitat linkages between viable breeding populations is one of the recovery
[[Page 25361]]
Habitat linkages or corridors providing vegetative cover can facilitate the movement of bears through agricultural (or other open) lands, particularly when bears reside in fragmented tracts of forest, as is the case for the Louisiana black bear (Weaver et al. 1990b, p. 347). Based on telemetry locations and visual observations, Marchinton (1995, p. 53) determined that wooded drainages were important travel corridors for movement between forested tracts. He noted that those drainages may facilitate movements across agricultural lands and may be important for dispersal outside the study area. Likewise, Weaver (1999, p. 67) found significant use of habitat linkages between larger forested tracts, including forested edges associated with bayous, their tributaries, various dry ditch bottoms, and brushy ditch and canal banks in various agricultural tracts. Bears were also observed to frequent certain areas of intact forest such as banks of rivers, sloughs, ditches, and bayous, and Weaver (1999, p. 82) suggested that the term ``habitat linkages'' may be more appropriate than travel corridors when referring to the remnant habitat features that link disjunct wooded tracts.
Beausoleil (1999, p. 62) observed that female Louisiana black bears would not move between woodlots unless they were connected by a forested corridor or were closer than 1,640 feet (ft) (0.5 km) apart. Anderson (1997, p.74 via T. Edwards, USFWS pers. communication) found that female bears would not travel between expansive agricultural fields that separated forested tracts by 4,541 ft (1.3 km) and observed that bears traveled along treelined ditches that were as narrow as 16 ft (5 m) in width (Anderson 1997, p. 74). Similarly, Van Why (2003, pp. 30, 46) observed Louisiana black bears using narrow strips of vegetation (less than 33 ft (10 m)) to travel through inhospitable habitats such as open fields. Weaver et al. (1990b, p. 347) recommended a 197ft (60m) buffer zone along waterways as a travel corridor or habitat linkage. Bears will travel through open habitat (Weaver 1999, p. 81), but they may travel farther from the forested edge when in a wooded corridor versus in an open field (Anderson 1997, p. 42).
Habitat linkages, as described in Louisiana black bear population studies, are generally described as narrow and linear in shape, most likely resulting from the fact that ditches and bayous are the only remaining features connecting habitat fragments within a population. Nonlinear habitat patches located between existing populations may also provide areas for bear movement. Such linkages increase the amount of forested habitat (Beausoleil et al. 2005, p. 408) and may serve not only as pathways for concealed travel, but may also provide other functions such as escape cover, bedding and denning sites, routes for juvenile dispersal, and avenues for genetic exchange (Weaver 1999, pp. 8283). Habitat linkages ranging from 2.5 ac to 12 ac (1 ha to 5 ha) can provide cover for black bears (Pelton and Van Manen 1997, p. 33). Smaller areas (i.e., 2.5 ac (1 ha)) may provide suitable movement paths for shorter, withinpopulation movements but may not be sufficient for establishing larger movement paths between populations. Beausoleil et al. (2005, pp. 409410) recommended the establishment of habitat corridors to reduce the isolation of forested habitats for black bears and suggested that corridor width should vary with length and increase with distance. Similarly, Cox et al. (1994, p. 35) suggested that black bears likely require broader habitat areas rather than thin corridors when connecting distant populations.
While there is scientific discussion regarding the relative
importance of wildlife corridors in general, they have been shown to be
important for black bears (Cox et al. 1994, p. 34). Furthermore, in
modeling spatial landscape structure and species dispersal, King and
With (2002, p. 33) found that habitat clumping may help mitigate the
negative effect that habitat loss has on dispersal success. Habitat
linkages (or corridors) are needed to facilitate bear movement between
habitat patches within and between black bear populations (BBCC 1997,
p. 54). Telemetry data on Louisiana black bear movements in the Tensas
River Basin demonstrate that habitat linkages should be considered in
management plans intended to ensure Louisiana black bear population
viability in fragmented habitats and to provide for the large home
ranges (particularly of males) needed for unimpeded breeding and dispersal (Weaver 1999, p. 106).
Food, Water, Air, Light, Minerals, or Other Nutritional or Physiological Requirements
The Louisiana black bear's diet is dominated by plant material throughout the year (Pelton 1982, p. 508; Anderson 1997, p. 77; Benson 2005, p. 20). A portion of the diet is made up of animal matter, primarily beetles and other insects (which are consumed yearround (Anderson 1997, p. 79)), and occasionally carrion (Pelton 1982, pp. 508509; Benson 2005, p. 27). Diets vary seasonally in relation to food availability as does habitat use (Nyland 1995, p. 53). After den emergence in the spring, bears utilize remaining fat reserves (Pelton 1982, p. 509). As this is generally a time of lower food abundance, bears may lose weight but will soon take advantage of any available proteinrich foods (Pelton 1982, p. 509). On the Deltic tracts, such items include grasses, sedges, oats, wheat, and beetles (Anderson 1997, p. 49; Benson 2005, p. 26). During the summer, food abundance and diversity increases, and soft mast, found primarily in forest openings, becomes a major food source. Soft mast may include such items as blackberry, grape, mulberry, sassafras, and paw paw (Weaver et al. 1990b, p. 344; Anderson 1997, p. 78; BBCC 1997, p. 18; Benson 2005, p. 26). Recently timbered areas can provide foraging opportunities for bears as they allow light penetration through canopy openings and provide rotting wood that harbors beetles and grubs (Weaver et al. 1990b, p. 344). Louisiana black bears were also observed using early successional areas (e.g., planted with trees or regenerating naturally) planted with trees (0 to 12 years) or by an open canopy and dense understory of shrubs, vines, and saplings (Benson 2005, p. 56, Table 4.1). Such areas provide food and cover similar to natural openings in forests.
Food availability during the late summer and fall is critical as bears need to increase their fat stores in preparation for winter dormancy and denning (Pelton 1982, p. 509; BBCC 1997, p. 18). Acorns and other hard mast are important food items during this period (Pelton 1986, p. 51; Benson 2005, p. 27). Extensive foraging may occur and bears may travel great distances in search of food (Pelton 1982, p. 509). It is not uncommon for a bear to gain one to two pounds of fat daily (Pelton 1986, p. 51). Bears will forage on agricultural crops, which may dominate the diet depending on availability (Nyland 1995, p. 59; Anderson 1997, p. 78; Benson 2005, p. 20).
An important factor affecting black bear populations appears to be
variation in food supply and its effect on physiological status and
reproduction (Rogers 1976, pp. 436437). Black bear cub survival and
development are closely associated with the physical condition of the
mother (Rogers 1976, p. 434). Cub mortality rates and female
infertility are typically greater in single or successive years of poor
mast production or failure (Rogers 1987, p. 53; Eiler et al. 1989, p.
357; Elowe and Dodge 1989, p. 964). Nutrition may affect the age of female reproductive maturity and subsequent fecundity
[[Page 25362]]
(Pelton 1982, p. 504). Reproduction may occur as early as 2 years of
age for black bears in high quality habitat; in poor or marginal
habitat, reproduction may not occur until 7 years of age (Rogers 1987,
pp. 5152, Table 8). Litter size may be affected by food availability
prior to denning (Rogers 1987, p. 53, Table 10). During periods of food
shortages, bears range farther in search of food. This increased
movement substantially increases their chances for human encounters and
humanrelated mortality (Rogers 1976, p. 436; Pelton 1982, p. 509).
These high mortality rates are suspected to be greater for yearling and
subadult black bear males dispersing from the family unit, and are
probably the result of starvation, accidents (e.g., vehicular collisions), and poaching.
Black bears undergo a period of winter dormancy that allows them to circumvent food shortages and severe weather (Pelton 1982, p. 508). Louisiana black bears generally enter dens in early December and emerge in midApril (Weaver 1999, p. 116, Table 4.1). They may remain somewhat active during this period and have been observed changing den sites and foraging, although their home range sizes are reduced (Weaver 1999, p. 115; Hightower et al. 2002, p. 16). Louisiana black bears use trees, brush piles, and ground nests for denning (Weaver 1999, p. 118; Hightower et al. 2002, p. 14). An individual bear may use one or more different den types, often within the same season (Weaver 1999, p. 118). Weaver (1999, p. 120) noted that most den trees were bald cypress, but also observed bear use of other species such as overcup oak and American sycamore. Den tree cavities appeared to result from broken tops or limbs and averaged approximately 49 ft (15 m) in height (Weaver 1999, p. 121). Den trees primarily occur along permanently flooded sloughs, seasonally flooded flats, lakes, bayous, and rivers (Weaver 1999, p. 130). Ground nests were located in wooded habitat and constructed from stacked palmetto and vegetation arranged in a wreath like manner. Many of the wreathlike nests included excavated depressions, but those created from stacked palmetto did not (Weaver 1999, pp. 121122). Nests were observed in forested habitat and constructed against a backdrop such as a felled log, a tree top, or the base of a tree (Weaver 1999, p. 122). In the Tensas population, thirteen of 17 nests were located in forested stands that were at least partially timbered within the last 5 years (Weaver 1999, p. 122). Brush pile dens were observed in residual tree tops that were felled during recent timber harvests (Weaver 1999, pp. 122; Hightower et al. 2002, p. 14). Trees large enough and sufficiently mature to contain useable cavities are almost always found in places inaccessible to logging (Marchinton 1995, p. 55), or are left standing due to their low economic value.
The importance of highquality cover for bedding, denning, and escape cover increases as forests become smaller and more fragmented, and as human encroachment and disturbance in bear habitat increases (Pelton 1986, p. 52). The thick understory found in some BLH forests and adjacent areas provides highquality escape cover, which is considered especially important where fragmented habitats put bear populations in closer proximity to humans. Bears frequently use forested areas and scrubshrub habitat as escape cover and as resting sites or ``daybeds'' (Weaver et al. 1990b, p. 347). Daybeds are generally shallow, unlined depressions excavated in soft ground or leaf litter (BBCC 2005, p. 13). Secure areas for bedding, denning, and escape can be found in cover that limits visibility, slows foot travel, and creates noise when traversed (Weaver et al. 1990b, p. 347). Sites for Breeding, Reproduction, or Rearing (or Development) of Offspring
The average age for first female reproduction varies widely across black bear studies; however, most describe breeding occurring between 3 years and 5 years of age (Weaver 1990, p. 5). Breeding occurs in summer and the gestation period for black bears is 7 to 8 months (Weaver 1990, p. 5). Delayed implantation occurs in the black bear; blastocysts float free in the uterus and do not implant until late November or early December (Pelton 1982, p. 505). Because of this, pregnant females are not subject to the nutritional drain of a developing fetus while they forage to increase fat reserves for winter torpor (Weaver 1990, p. 5). Additional information on female habitat requirements is described in the ``Space for Individual and Population Growth and Normal Behavior'' discussion above. Females give birth during the denning season. The normal litter size is two, although litter sizes of one to four cubs (and rarely five) do occur. Cubs are altricial (helpless) at birth (Weaver 1990, p. 5) and generally exit the den site with the female in April or May. Young bears stay with the female through summer and fall, and den with her the next winter. The young disperse in their second spring or summer, prior to the female's period of estrus (Pelton 1982, p. 505). Estrus starts when the female becomes physiologically capable of reproducing again. However, not all females produce cubs every other winter; reproduction is related to physiological condition (i.e., female bears that do not reach an optimal weight or fat level may not reproduce in a given year) (Rogers 1987, p. 51).
Females give birth while in their winter dens. Den site characteristics were described in more detail in the ``Cover or Shelter'' discussion above. Secure den sites for reproduction are particularly important as the young would not survive without their mother should she abandon her den because of disturbance. Benson (2005, p. 84) found that female reproductive status affected den type use, as females with cubs used trees for dens more frequently than ground dens. However, Hightower et al. (2002, p. 14) did not detect differences in den type use by females based on their reproductive status.
Tree dens may be an important component for female reproductive success in areas subject to flooding (Hellgren and Vaughan 1989a, p. 352). Den trees located in cypress swamps would appear to provide an increase in security (e.g., decrease in disturbance) compared to ground dens. The availability of den trees, however, does not appear to be a limiting factor for reproductive success (Weaver and Pelton 1994, p. 431); den trees may not be necessary for Louisiana
FOR FURTHER INFORMATION CONTACT James Boggs, Field Supervisor, U.S. Fish and Wildlife Service, Louisiana Fish and Wildlife Office, 646 Cajundome Boulevard, Suite 400, Lafayette, LA 70506; telephone 337291 3100; facsimile [3372913139]. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 8008778339.
14 CFR Part 39 40 CFR Part 52 14 CFR Part 71 33 CFR Part 165 26 CFR Part 1 50 CFR Part 679 33 CFR Part 117 40 CFR Part 180 44 CFR Part 67 50 CFR Part 17 47 CFR Part 73 50 CFR Part 648 14 CFR Part 97 33 CFR Part 100 40 CFR Part 63 50 CFR Part 622 26 CFR Part 301 39 CFR Part 111 44 CFR Part 65 40 CFR Parts 52 and 81 40 CFR Part 271 14 CFR Part 23 47 CFR Part 76 40 CFR Part 300 21 CFR Part 522 50 CFR Part 660 50 CFR Part 229 47 CFR Part 64 7 CFR Part 301 14 CFR Part 25