Louisiana Black Bear

Ursus americanus luteolus

Description

The Louisiana black bear is a huge, bulky mammal with large males weighing more than 600 lbs (272.4 kg). The species has long black hair, with brownish or cinnamon color phases often found in western parts of its range. The tail is short and well-haired. The facial profile is rather blunt, the eyes small, and the nose pad broad with large nostrils. The muzzle is yellowish brown and a white patch is sometimes present on the lower throat and chest. There are five toes on the front and hind feet with short curved claws.

Behavior

Infants are born in the mother's den sometime between December to February. The newborns weigh only about 0.5 lbs (0.2 kg), have little or no hair, and their eyes are closed. When the fur begins growing it is brown, but within a month or so it is quite black. Sharp teeth are well-developed within a couple weeks. The cubs grow rapidly and leave the den in April or May, weighing about 5 lbs (2.2 kg). Cubs begin climbing early, usually within three or four months. Parental care is given exclusively by the female, and usually lasts one and one-half years. Nursing continues for approximately seven months after birth, but during this time the cub is eating a variety of other foods. The second winter, the female and her cubs den together. By the following spring the cubs could weigh 40 to more than 100 lbs (18.2 to more than 45.4 kg) and be as big as the female. Late in the spring or summer the unit splits up, each going its separate way.

Females go into estrus sometime in June or July. Males follow scent trails laid down by the estrous females, mate, usually only staying together for one or two days. This species shows delayed implantation. In most other mammals, an egg fertilized by male sperm attaches itself to the wall of the female's uterus soon after mating. There it grows steadily until birth. In this species, the fertilized egg, having developed into a tiny ball, simply floats in the fluid within the uterus. Only when the mother is hibernating in her den does the fetus attach itself to the wall of the uterus and begin again to grow. The total time for growth is only 42-46 days, though pregnancy lasts about seven months. A normal litter consists of one to three cubs. Females normally give birth every other year, due to the long lactation period.

This species exists in ranges throughout its territory. Ranges do not usually overlap with other individuals, but may if there is a large amount of food in that territory. The species does not migrate, but does move freely throughout its range. There have also been examples of a homing instinct in this species. Individuals have traveled up to 140 mi (225.3 km) to return to its range.

Louisiana black bear, like other members of Ursidae, are omnivorous, eating both animal and vegetable foods. Most of the species' diet is made up of vegetable matter. In the spring and fall, about half the species' diet is vegetation, rising to 80% in the summer. Much of the non-insect animal matter that the species eats is carrion, the bodies of animals that have died of starvation or other causes. Studies in the Great Smoky Mountains National Park and nearby areas show that grasses, herbs, berries and nuts make up 81% of the species' food; animal matter, most of it bees and beetles, is 11%; and garbage and other artificial foods are 8%.

Food habits show seasonal differentiation. When the species first comes out of its den in the spring, it depends mostly on grasses and weeds, along with the carrion of animals. Throughout the summer, berries and insects make up most of the species' diet. In early fall, some berries are still eaten along with the late-ripening species such as the gallberry. Late fall brings a rich diet of nuts to give the species extra energy as denning draws near.

The Louisiana black bear hibernates over the winter months. The length of hibernation depends primarily on the climate in the habitat. The species in Alaska hibernates up to seven months, in North Carolina it hibernates about five months, and in Florida's Apalachicola National Forest the species may not hibernate at all. Another factor that affects hibernation is food supply. If supplies are plentiful, hibernating may come later in the season. Hibernating individuals usually lower their heart rates from a normal resting rate of 40 beats per minute to 10 beats per minute over a period of two to four weeks. The species does not eat, drink, urinate or defecate during the hibernation period. It can be aroused quickly, returning to a normal heart rate in about half an hour. It is not certain how long the Louisiana black bear hibernates.

Habitat

The Louisiana black bear is found in a wide range of habitat. It is found most often in bottomland hardwood areas, such as oak, maple, and beech of the Tensas and Atchafalaya River Basins. It may also use marshes along the lower rim of the Atchafalaya Basin and agricultural lands such as sugar cane and soybeans in other areas. As a rule the species can use many different habitats, but does require large areas of relatively undisturbed forest. Other characteristics the species' habitats have in common are dense underbrush for food and cover, and trees suitable for climbing.

Distribution

This species once occurred throughout southern Mississippi, all of Louisiana, and eastern Texas. The historic range included all Texas counties east of and including Cass, Marion, Harrison, Upshur, Rusk, Cherokee, Anderson, Leon, Robertson, Burleson, Washington, Lavaca, Victoria, Refugio, and Aransas; all of Louisiana, and the southern Mississippi counties south of and including Washington, Humphreys, Holmes, Attala, Neshoba, and Lauderdale.

Presently occupied habitat in Louisiana consists of two core areas, the Tensas and Atchafalaya River Basins. The total habitat area within these two areas is 200,000-228,000 acres (80,937.5-92,268.7 hectares), of which half is privately owned. Counties of past known populations in Louisiana include: Mary, Carroll, Madison, Tensas, Concordia, Point Coupee, St. Martin, Iberia, and Iberville. In Mississippi the species occurs in small numbers in the Mississippi Delta and in the loess bluffs bordering the Mississippi River floodplain. This species is known to occur on the Chettimanchi Reservation, the Fort Polk Army base, the Barks-dale Air Force Base, and an Army ammunitions plant. Other federally-owned lands on which the species occur include: the Ozark National Forest, Jean Lafitte National Park, Atchafalaya National Wildlife Refuge, and the Great Smoky Mountains National Park.

Threats

The major cause of the Louisiana black bear's decline is loss of habitat, mainly due to agriculture. Suitable habitat for the species has been reduced by more than 80% as of 1980. The remaining habitat has been reduced in quality by fragmentation due to the intrusion of humans and their structures (i.e. highways), thereby stressing the remaining population of individuals. The original 25 million acres (10.1 million hectares) of bottomland forest of the lower Mississippi River Valley has been reduced to five million acres (two million hectares), and through the early 1980s another 165,000 acres (66,773.4 hectares) were being cleared annually. Some of the Mississippi River Delta counties in the lower Yazoo River Basin may have as little as five percent of the original bottomland hard-woods.

Of the habitat presently occupied by the Louisiana black bear in the Tensas River Basin, only 15% (about 100,000 acres or 40,468.7 hectares) of the original bottomland forest remains; in Atchafalaya River Basin, only about 100,000-128,000 acres (40,468.7-51,780 hectares) of forested lands remain. Nearly one half of the occupied habitat in the Atchafalaya River Basin is privately owned and under no plans for protection through conservation easements or acquisition.

Illegal trapping and killing of this species has been another limiting factor for the species. The appearance of an abnormally low density of this species in the Atchafalaya River may be an indicator of considerable illegal killing on private and public lands and needs to be studied further.

Conservation and Recovery

Studies are ongoing on the Tensas National Wildlife Refuge, in the lower Atchafalay River Basin and in Mississippi to delineate areas used by the species and assess management needs, and maps are in preparation that will show occupied habitat, areas of occasional sightings, potential habitat and possible corridors. Development of a restoration plan has already been initiated by the Black Bear Conservation Committee. The U. S. Fish and Wildlife Service (FWS) will make a critical habitat determination and assess whether a designation of critical habitat is prudent.

Maintaining occupied habitats in some form of timberland condition may be the single most critical factor in conserving this species. Like other members of its species, the Louisiana black bear is not an old growth species; nor can it survive in open cropland conditions. It has been found that an abundance of the species' foods were produced following timber harvests, and that individuals also utilized these cutover areas for escape cover, and in some cases, actually used treetops remaining from logging operations as winter denning sites for birthing of cubs. This has led the FWS to believe that normal forest management will provide habitat diversity for the species. Candidate den trees, such as bald cypress and tupelo gum with visible cavities occurring near rivers, lakes, streams, bayous, sloughs, or other water bodies, in occupied habitats are to be maintained. Stricter control of the illegal taking of the species needs to be enforced.

Contacts

U.S. Fish and Wildlife Service
Regional Office
P. O. Box 1306
Albuquerque, New Mexico 87103
http://southwest.fws.gov/

U.S. Fish and Wildlife Service
Regional Office
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

Texas Parks and Wildlife Department
4200 Smith School Rd.
Austin, Texas 78744

Austin Ecological Services Field Office
Harland Bank Building
10711 Burnet Rd., Suite 200
Austin, Texas 78758-4460
Telephone: (512) 490-0057
Fax: (512) 490-0057

Jackson Ecological Services Field Office
6578 Dogwood View Parkway, Suite A
Jackson, Mississippi 39213-7856
Telephone: (601) 965-4900
Fax: (601) 965-4340

References

Ford, B. 1981 Black Bear Spirit of the Wilderness. Houghton Mifflin, Boston. 182 pp.

U.S. Fish and Wildlife Service. 7 January 1992. "Endangered and Threatened Wildlife and Plants; Threatened Status for the Louisiana Black Bear and Related Rules." Federal Register. 57:588-594.

U.S. Fish and Wildlife Service. 1990. Listing Proposals-June 1990. Endangered Species Technical Bulletin. 15(7):4.

U.S. Department of Defense. 1991. Threatened and Endangered Wildlife Species on U.S. Army Installations. p. 154.