Monitoring bear movements has
revealed that bears are more active from dusk through dawn, although
daytime activity is not unusual and varies somewhat by season.
Home range sizes vary from year to year, and from season to
season, depending on population density, food availability, sex, age,
and reproductive status. Home ranges for males may increase during
the mating season in summer and both male and female bears move
extensively in fall when foraging to put on winter fat reserves.
Bear activity revolves around the
search for food, water, cover, and for mates during the breeding
season. Male black bears move much greater distances than females,
often covering 2 to 8 times the area of females. Some adult male
bears in the Tensas basin ranged up to 35 miles from their capture
site.
Estimates of average annual home range sizes indicate adult
males use 20,000 acres and adult females use 5,000 acres, although
individual home ranges can vary widely. For example, one adult male
in the upper Atchafalaya Basin ranged over 85,000 acres.
Bears often utilize “daybeds”
under forested cover. These sites are usually shallow, unlined
depressions scratched in soft ground or leaf litter. Mothers with
cubs often bed at the base of the largest tree in the area. The
female sends the cubs up the tree if she senses danger and either
climbs the tree with them, remains at the base of the tree or exits
the area alone. Sometimes bears will rest above ground in the crown
or lower branches of a tree.
Older adult males exert social
pressure on younger bears, especially during the spring and summer
breeding season, forcing them to disperse to other areas. Dispersal
of bears, especially young males, puts them at considerable risk.
Their movements take them to unfamiliar areas. In their attempt to locate a new home, they cross roads
and highways, increasing the chances of being hit by motor vehicles,
and they will likely cross areas inhabited by humans. This creates
potentially dangerous situations for both humans and bears. Because
of stress and increased human interaction, dispersing bears have
a reduced chance of survival.
Travel corridors
are important to the movements of adult bears and the dispersal of
juveniles through agricultural lands, particularly when they are
residing in separate tracts of forested lands or in a severely
fragmented forest. Females are especially reluctant to move from one
forest block to another if there is no vegetative cover linking the 2
areas.
Data from studies of radio-collared
bears and observation of bear signs document that uncleared drains,
ditches, bayous, and river banks are frequently used to traverse open
land when moving from one forested tract to another. Drainage ditches lined with trees and brush, even as narrow as
30 feet wide, are used by bears to pass through open agricultural
areas. Based on comparative data, this may be a minimum width for a
viable corridor; however, a good rule of thumb would be “the wider
the better.”