Spatio-temporal ecology, habitat use and population size of brown bears (ursus arctos) in Yusufeli, Turkey

Ambarlı, Hüseyin
Brown bear is the largest mammal in Turkey and its main distribution lies in the Black Sea and Eastern Anatolia Regions. Its basic ecology is almost unknown in Turkey, except for a limited number of studies. This study aims to determine the spatio-temporal ecology and habitat use of brown bears in the Kaçkar Mountains, and to estimate their population size in the Özgüven Valley and Yusufeli, both firsts for Turkey. The study area is primarily covered with conifer and oak stands, but sparse mixed shrubland occurs in the Mediterranean climate influenced lower parts. GPS-GSM telemetry on seven captured bears (5 males and 2 females) was the main field technique used in this study. Other methods include monitoring via camera trapping, visual direct observations, and counting cubs of the year. Bears were fitted with GPS-GSM collars and tracked for 3 to 603 days. Mean home range size (HRS) was calculated by 95% kernel and MCP estimators for three different samples sizes.95% MCP for all positions produced a home range size of 19.91 ± 8.89 sq. km. for females, and 130.68 ± 102.95 for males. On average, males and females move at rates of 199 m/h and 129 m/h, respectively. Males hibernate around 140 days whereas females around 150 days and at lower elevations than males. According to camera trapping results, bears are generally active at twilight whereas activity data loggers produced disparate results for tracked bears. Resting patterns showed that bears may also rest at midnight. Estimated population density per 100 km2. is 24.50 ± 1.74 individual using the Fcub method and 23.85 ± 2.51 using the mark–resight method. Captured bears indicated nonrandom distribution on habitat use and selected productive croplands and shrublands than other types of vegetation. Brown bear HRS in the Kaçkars is smaller than reported from most countries. The large female-male HRS difference is probably due to polygamous mating system, sexual dimorphism, hard mast availability, high population density, and female’s habitat exclusivity as a result of high tolerance by the local people in contrast with most northern countries. Although primary productivity is used to explain high population density and small HRS in other countries, the low productivity in the study area cannot explain the observed density and HRS difference. These findings will construct a scientific basis for brown bear management and conservation in Turkey.
Citation Formats
H. Ambarlı, “Spatio-temporal ecology, habitat use and population size of brown bears (ursus arctos) in Yusufeli, Turkey,” Ph.D. - Doctoral Program, Middle East Technical University, 2012.