Abstract 136 – Movement patterns of brown bears in a desert environment

Delgerchimeg Dawaaasuren, Amgalan Luvsanjamba, Harry Reynolds, Jerrold
Belant, Andreas Zedrosser

The Gobi brown bear lives in the Great Gobi Strictly Protected Area A (GGSPAA), Mongolia, and
is considered the most endangered bear population in the world with a population size of ~40
individuals. The Gobi Desert has very few water access points, the shortest distance between
neighboring water points is ~100 km. The climate is harsh with very cold winters and very hot
summers (temperature range -31 to +40C) and very little precipitation. The main goal of this
study was to understand the activity patterns of bears living in a desert environment. We
captured and GPS-collared 19 bears (4 females, 15 males, 3-21 years old) in the core area of the
GGSPAA during 2005-2018. We defined activity as the straight-line distance between two
consecutive 24-hour GPS locations. Compared to the fall months, male bears were significantly
more active from March until the beginning of July, which coincides with the mating season. In
comparison, female activity was significantly higher during the period end of May until August,
which overlaps partly with the mating season but also with the onset of hyperphagia.
The mean monthly movement activity was similar among the sexes. The longest mean day
distances recorded in males ranged from 177 to 839 meters. The longest mean daily distances
recorded moved were over 42km during the mating season. Females showed mean daily
movement distances from 304 to 847 meters, and the longest mean daily movement distances
were over 26 km during the mating season.However, the home range size significantly differed
between the sexes, and male home range sizes increased from April to June, while female
home range remained the same during this time period. To our knowledge, these are the first
data on activity patterns of bears living in an extreme desert environment.