Linda Benedict | 5/5/2005 6:21:26 PM
The Louisiana black bear was once distributed throughout eastern Texas, southern Arkansas, Louisiana and southern Mississippi. By the early 1900s, however, Louisiana black bear populations in this region were decimated from excessive harvest and habitat loss and degradation. Only about 300 Louisiana black bears are left in Louisiana, and they are restricted to the Tensas and Atchafalaya river basins and isolated sections along the Mississippi River corridor. A few Louisiana black bears live in the lower East Pearl River and the lower Pascagoula River basins in southern Mississippi.
Because of concern about the future of this species, three states – Louisiana, Mississippi and Texas – have listed the Louisiana black bear as protected. In 1992, further protection was provided through listing as threatened under the federal Endangered Species Act.
Through the cooperative efforts of state and federal agencies, research has been conducted on the Louisiana black bear for more than a decade. This research has detailed various aspects of bear activity, movements and habitat use. Using this database, a Black Bear Restoration Plan and a Black Bear Recovery Plan were developed in cooperation with the U.S. Fish and Wildlife Service and the Louisiana Black Bear Conservation Committee. The ultimate goal of conducting preliminary research and developing restoration and recovery plans is the de-listing of the Louisiana black bear as protected and, ultimately, removal of it from threatened status.
Black Bear Locations
Louisiana black bears live in three places in Louisiana (Figure 1). The northernmost population is found in the Tensas River basin, and the southernmost population is in the lower Atchafalaya River basin. A third population is sandwiched between these two in the Morganza floodway system. To remove the Louisiana black bear from threatened status, an additional population must be established to provide the opportunity for movement of bears among existing populations. To accomplish that goal, the U.S. Fish and Wildlife Service, in cooperation with LSU AgCenter and the Louisiana Department of Wildlife and Fisheries, chose the Red River Wildlife Management Area and surrounding lands as the site for a bear restoration effort.
Restoration of rare species has recently become an important conservation technique, particularly for large mammals such as black bears. Success stories include the grizzly bear and gray wolf in the West. Black bears are capable of long-range movements, and dispersal is often related to sex, age, population density and habitat quality. Subadult male bears are often forced to disperse because of competition with older males, whereas young females frequently establish home ranges within areas maintained by their mothers. Because of this life history strategy, natural expansion of bear populations is slower for females. Furthermore, natural expansion of the Louisiana black bear throughout Louisiana is hampered by habitat fragmentation and lack of suitable travel corridors. Because of these inhibiting factors, establishment of sustainable bear populations in isolated bottomland hardwood habitats is uncertain without human intervention.
Black bears have a strong homing tendency, which in the past has reduced the effectiveness of relocation projects designed to bolster populations. In fact, most previous translocation projects have failed because bears simply leave the area chosen for relocation immediately following the release. Recently, however, relocations of adult females with cubs have been successful. The technique is termed a “soft release” and likely works because movements of the female are restricted by maternal instincts that mandate she care for her cubs. As females remain on the release site, they become familiar with their surroundings and eventually establish a home range there.
Because this “soft release” method had been successful with other bear populations, LSU AgCenter researchers decided to try it with the Louisiana black bear. During March 2001, four female black bears and their nine cubs were removed from their winter dens and relocated to the Red River Wildlife Management Area. Two females were taken from the Tensas River basin population and two from the lower Atchafalaya River basin. Each female was fitted with a radio transmitter and placed within a den constructed by Fish and Wildlife Service personnel.
Following the release, each female was monitored intensively. To date, the relocation effort has been a success, and a considerable amount of information important to future releases and restoration of bear populations has been gathered. Three of the four females remained on the Red River Wildlife Management Area. The fourth abandoned her two cubs, which is not unusual for these bears under stressed conditions. She traveled about 60 miles to the southwest and has established a home base there.
Because she did that, this is considered a success, too. Her two cubs were rescued and successfully adopted by a black bear mother in the lower Atchafalaya region. Cub survival for the species is about 50 percent. Because of this project’s success, a five-year research/restoration program has been initiated, with the ultimate goal of establishing a sustainable black bear population in the Red River Wildlife Management Area. Future releases will occur on the Three Rivers and Grassy Lake Wildlife Management Areas, as well as the Lake Ophelia National Wildlife Refuge. Also, AgCenter personnel will trap bears throughout the project to gather information on the effects of removing bears from source populations.
With only 300 Louisiana black bears spread among three isolated regions, the chance for the species’ survival in the state is bleak unless genetic exchange occurs among the populations. The only way to ensure this is to create an additional population to genetically link the two existing populations and to maintain critical habitat. About 150 of the bears live in the Atchafalaya Basin, an area fast becoming encroached upon by urban sprawl. Movement north is restricted by Highway 90. Some are killed by the fast-moving vehicles.
The establishment of an additional subpopulation of black bears on the Red River Wildlife Management Area offers a corridor between two of the bear subpopulations and the opportunity for cross-breeding and thus improved gene flow. Furthermore, the LSU AgCenter research program will provide knowledge about the processes affecting the Louisiana black bear and the ecology of the species. To date, information collected during the initial release has provided insight into use of land corridors by bears, as well as dynamics of bear movements following release. For instance, each female has traversed about 4,000 acres of the release site during her movements and has used a variety of habitats to fulfill daily requirements. Last, the black bear restoration program will provide a rare opportunity to assess the feasibility of using soft release relocation techniques to ensure persistence of the Louisiana black bear.