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Moving Bears to Unoccupied Habitats
The Louisiana black bear exists mostly
in small, isolated populations living in fragmented patches of
bottomland hardwood forest. As a wildlife population grows, ideally
it would expand into new areas of suitable habitat. Unfortunately,
the bear populations and suitable habitats in the region are
separated far enough from each other that this natural expansion
becomes difficult. The ability of male black bears to range far and
wide is well known, however, females generally remain in the same
small area throughout their lives. While young male bears disperse
from their mother, young females tend to set up their home range near
their mother. This behavior, coupled with the fragmented habitat,
have prompted bear managers to look seriously at moving bears from
existing populations to suitable habitat where bears are rare or
absent (called repatriation). The goal of repatriation is to
establish a viable population of bears that would help close the gap
between isolated bear populations.
Moving bears from one area to another
is no easy task, and getting them to stay generally where you put
them is even more difficult. Bears have a remarkable homing instinct
and quite often show extensive post release movements, but
researchers now believe they have developed a method that will work.
Biologists with the Pennsylvania Game
Commission developed a new “soft release” translocation
technique, where adult females with newborn cubs from an existing
population are moved from their winter dens to artificial dens at a
release site. Because cubs cannot travel far distances when they
emerge from dens, the mothers are likely to stay in these new areas.
Once females can be established in an area, males show up on their
own in their search for mates and set up their own home ranges.
Researchers at the University of
Tennessee compared the “winter den release” method with another
soft release method, which involves capturing bears and holding them
in pens to acclimate them for 2 weeks in the new release area.
Researchers found winter den release was a much more effective
technique. Bears were monitored after den emergence, and the winter
den release bears had a higher survival rate and stayed closer to the
release sites than with the other method. After these translocation
successes, bear biologists in Louisiana and Arkansas began looking at
the repatriation possibilities in the lower Mississippi Valley. In
Arkansas, bears are being moved from White River National Wildlife
Refuge (NWR) to Felsenthal NWR. In Louisiana, bears are moved from
Tensas River NWR and private lands to Lake Ophelia NWR and Red River
Wildlife Management Area.
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