Wild Life Ecology

Elective course spring semester 2007

Translocation of bears: The answer to the problems between humans and bears?

 Illustration 1 : Adult black bear lies in the grass. (National Park Service, 2007)

Berit Hoemsnes

Szent István University, Budapest

Bears.

The Bears belong to the family Ursidae and are one of our large carnivores. The family consists of a number of species which differ in many aspects. Examples are for instant the kodiak bear, Ursus arctos middendorffi, which is the largest, while the sun bear, Helarctos malayanus, is the smallest, not larger than a dog. The bears populate almost all habitats, from tropical forests, e.g. the sun bear, to the arctic snowfields, e.g. the polar bear (Wikipedia, 2007a).

The bear is a solitar animal, but can temporary group with other bears. This occurs mainly when there is plenty of food in the area. An example is when brown bears in Alaska gather in the same rivers to feed on the salmon which is swimming up the rivers to reach their spawning location (Wikipedia, 2007a).

The bear is an omnivore and can therefore have a very composite diet. A bear’s diet can consist of almost everything form vegetable, e.g. berries, fruits and roots, to fish and deer. Some bears can have a more specialized diet, e.g. the giant panda, Ailuropoda melanoleuca, which have a diet consisting on 99 % bamboo (Wikipedia, 2007b). Bears usually travel over large distances to find food, and since bears have a especially good memory they usually return to locations where they know they have found food before, even if this was years ago (Wikipedia, 2007a). A bear has also a well developed sense of smell, and it is therefore important to carefully pack away all your garbage when you are travel in an area which is known to be habitat for bears. If you do not, the bears may associate the smell of food with the smell of humans (Brunberg, 2007)

Translocation.

Translocation of carnivores has in general been a standard method to deal with “problem-animals” (Linnell et. al., 1997; Cobb, 1981; Rogers, 1988; Gunther, 1994). That is animals which cause problems for humans, by depredating on livestock or other conflict behaviours. Translocation means that a specific wild animal is captured alive and transported to another area and released there. In the case of releasing there are two methods: hard release and soft release.

Hard release is when the animal is released immediately at the release site, while soft release is when the animal is held in a restricted area at the release site for days, weeks, or months before it is set free. Since the soft release method is more expensive than the hard release method, almost all translocations are hard releases (Linnell et. al., 1997).

Many animals experience post-release movements when they are released in an unfamiliar environment after being translocated. Post-release movements means that the animal does not stay at the release point, but starts to wander. In many cases they return to their original capture point. Also many animals continue their problematic behaviour at the release point. Often is this because the release point has a conflict potential (Linnell et. al., 1997).

Translocations of bears have been a common procedure, especially with the black bear. The black bear, Ursus americanus, has been one of the most translocated carnivores (Linnell et. al., 1997; Bowyer and Brown, 1988). These translocations have usually been carried out due to livestock depredation or other conflict behaviours (Linnell et. al., 1997; Massopust and Anderson, 1984; Fies et. al., 1987; Armistead et. al., 1994). Many of the translocated individuals showed a strong non-random homing instinct (Linnell et. al., 1997; Rogers, 1984, 1986, 1988; Table 1). This lead to large post-release movements and larger amount of successive homing (i.e. the bear successfully returns to its capture point). Adult males have shown to have the strongest homing instinct (Linnell et. al., 1997; Rogers, 1986; Fies, et. al., 1987) while younger animals in general have the weakest homing instinct (Linnell et. al., 1997; Rogers, 1986). 

Also the grizzly/brown bear, Ursus arctos, shows similar homing instinct as the black bear (Linnell et. al., 1997).

But is translocation of bears that get in conflict with human interests the best solution to the problem or do it simply move the problem to an other area? And what about the bears, do they suffer from being translocated?

The main data of translocation of bears are in North America. If we look at table 1, we see that the percentage of bears that successfully return to their capture point is high. The table also shows that the translocation distance affected the bears homing success, i.e. larger translocation distance equals less percentage of successfully homings. The previously mentioned strong homing instinct of bears, clearly make the action of translocating the animal more difficult. This characteristic instinct must therefore also be taken in consideration when a translocation is planed. A translocation of a bear where the goal is that the animal stays away from its capture point and preferably at its release site requires knowledge about this instinct. Even though this is taken in to consideration there is still a high probability that the bear will return to its home. When translocation is thought to be the problem solver, it is important to estimate if the release point is suitable.

It has to have large enough area which lacks a conflict potential. Many translocations shows that the release area has a conflict potential and the bear therefore continue its conflict behaviour at its new location. This way the problem has only been moved from one place to another, causing the bear a lot of strain and giving the resources used to translocate the bear in the first place no value.

An experimental translocation of 47 Alaskan brown bears showed that most of the adults had successive homing, even though the mean distance was 200 km. Those who did not return were generally released further away than the ones that returned. The longest distance that one of the bears travelled was 258 km. Not one of the bears that were translocated stayed at the release point (Linnell et. al., 1997; Miller and Ballard, 1982).

Some studies show that bears which have been translocated have a negative reproductive rate and the cub-mortality is higher. A study made in Virginia on black bears, showed that female bears had a low reproductive rate during the first winter after being translocated. (Linnell et. a.l, 1997; Comly and Vaughan, 1995). This was also the case in another study regarding brown bears. (Linnell et. al., 1997; Miller and Ballard, 1982; Brannon, 1987) Other studies on black bears show that the ability to survive do not seem to be different between translocated and non-translocated individuals, the exceptions are cubs of the year. They seem to have a higher mortality rate when they were transported together with their mother. (Linnell et. al., 1997; Rogers, 1986). Regarding the brown bear, both cubs and yearlings had a higher mortality rate. This was the case even though their mother survived the translocation. (Linnell et. al., 1997; Miller and Ballard, 1982; Brannon, 1987).

 Illustration 3: Euroasian Brown Bear (Wild

 About The World, 2007) 

In Europe translocation is not as widely used as in North America, but there are data that shows that translocations have not been successive. In Norway a male brown bear were translocated 124 km, but used only 21 days to return home were it was killed by a train. Another bear was translocated 250 km due to depredation on sheep, but this one also return to its capture point. It took this bear 2 weeks to return and it started to kill sheep immediately on the same property as it had been captured. (Linnell et. al., 1997; Wabakken and Martmann, 1994; Rauer, 1995).

Is translocation the answer to the problems between humans and bears?

The data above suggest that translocation of bears have a low success rate, a success rate to low to defend the high amount of translocations being done. The data also shows that it in almost all cases do not solve the problem between bears and human interests. They rather suggest that the translocations apply the bears extra strain and suffering for no good reason.

These translocations were all carried out using the hard release method. This might suggest that this method is not good enough. Use of the soft release method has not being practised with problem animals, and therefore one can not say if translocation with use of this method will give more beneficial results.

References

Armistead, A.R., Mitchell, K. and Connolly, G.E. (1994) Bear relocations to avoid bear/sheep conflicts. Proc. Vert. Pest Conf. 16, 31-5.

Brannon, R.D. (1987) Nuisance grizzly bear, Ursus arctos, translocation in the Greater Yellowstone Region. Can. Field. Nat. 101, 569-75.

Brunberg S. (2007) Is the brown bear dangerous?: http://www.bearproject.info/english/bearproject.php. Available 02.05.07.

Bowyer, R.T. and Brown, R.D. (1988) Translocation of animals in Alaska. In Translocation of Wild Animals (L. Nielsen and R.D. Brown, eds) pp. 10-20. Wisconsin Human Society.

Cobb, S. (1981) The leopard – problems of an overabundant, threatened, terrestrial carnivore. In Problems in Management of Locally Abundant Wild Mammals (P.A. Jewell and S. Holt, eds) pp. 181-92. London: Academic Press.

Comly, L.M. and Vaughan, M.R. (1994) Survival and reproduction of translocated Virginia blac bears. Int. Conf. Bear Res. Manage. 9, 428-37.

Fies, M.L., Martin, D.D. and Blank, G.T. (1987) Movements and rates of return of translocated Virginia black bears. Int. Conf. Bear Res. Manage. 8, 369-72.

Gunther, K.A. (1994) Bear management in Yellowstone National Park. Int. Conf. Bear Res. Manage. 9, 549-61.

Linnell, J.D.C., Aanes, R., Swenson, J.E., Odden, J. and Smith, M.E. (1997). Translocation of carnivores as a method for managing problem animals: a review.

Massopust, J.L. and Anderson, R.K. (1984) Homing tendencies of translocated nuisance black bears in northern Wisconsin. Proc. East. Workshop Black Bear Manage. Res. 7, 66-73.

Miller, S.D. and Ballard, W.B. (1982) Homing of transplanted Alaskan brown bears, J. Wildl. Manage. 46, 869-76.

National Park Service (2007). http://www.nps.gov/biso/naturescience/blackbear.htm Available 02.05.07.

Rauer, G. (1995) First experiences with the release of two female brown bears in the Alps of eastern Austria. Int. Conf. Bear. Res. Manage. 49, 469-78.

Rogers, L.L. (1984) Homing by black bears and other large mammals. Proc. East. Workshop Black Bear Manage. Res. 7, 76-7.

Rogers, L.L. (1986) Effects of translocation distance on frequency of return by adult black bears. Wildl. Soc. Bull. 14, 76-80.

Rogers, L.L. (1988) Homing tendencies of large mammals, a review. In Translocation of  Whild Animals (L. Nielsen, and R.D. Brown, eds) pp. 76-92. Wisconsin: Wisconsin Humane Society.

Wabakken, P. and Martmann, E. (1994) Sluttrapport for bjørn-sauprosjektet i Hedmark 1990-1993. NINA forskningsrapport 058, 1-49.

Wikipedia, the free encyclopedia (2007a): http:/www.wikipedia.org/wiki/Bears. Available 02.05.07.

Wikipedia, the free encyclopedia (2007b): http://en.wikipedia.org/wiki/Giant_panda. Available 02.05.07.

Wikipedia, the free encyclopedia (2007c): http://en.wikipedia.org/wiki/Brown_bear. Available 02.05.07.

Wild About The World (2007): http://www.wildabouttheworld.com/gallery/data/505/Brown-Bear.jpg. Available 02.05.07.