PhD‐theses - Ethologische Gesellschaft

Research Update
MICROHABITAT SELECTION BY EUROPEAN BISON (BISON BONASUS) IN BIAŁOWIEŻA PRIMEVAL
FOREST, POLAND
Tilman C. Schneider
tilman.carlo@googlemail.com
Master Thesis, supervised by Prof. Dr. Peter Kappeler, Anthropologie/Soziobiologie, Georg‐August
Universität Göttingen, Dr. Rafał Kowalczyk, Mammal Research Institute, Polish Academy of Sciences
Resting site selection by European bison (Bison bonasus, L., 1758), the largest terrestrial
mammal of Europe, was studied in the free‐ranging population in Białowieża Primeval Forest
(Poland) in 2009‐2010. In total, 104 sites of 21 bison (both collared and uncollared) were
analysed to determine the most important microhabitat characteristics selected by resting
bison during summer and winter. I examined whether bison selected characteristic resting
sites providing shelter from disturbances and precipitation, and how supplementary winter
feeding influenced the microhabitat selection by bison. Resting sites were identified on the
basis of GPS locations and activity records, as well as direct observations, and were
compared with control sites. In 95% of locations prescribed on the basis of GPS collar data, a
bison bed was found. Habitat types, forest stand characteristics and distances of the sites to
roads and open areas and the harassment by pest insects were recorded. Microhabitat
selection by bison did not differ significantly between the sexes. During summer and winter,
bison resting sites displayed a high tree density, low visibility and high complexity (structures
providing cover). Summer resting sites were also characterised by a lower abundance of
blood‐sucking insects and denser canopy than control sites. Winter resting sites showed a
lower complexity and higher visibility than summer sites, and were less often located in
mixed forest habitats. During winter, bison rested more frequently in forest below 50 years
of age than in older forest. Resting sites of non‐supplied bison were more often located in
young coniferous forests, were lower in visibility and situated closer to open areas than sites
of bison using supplementary winter feeding, suggesting a trade‐off between food and
cover. Statistical models revealed tree density, visibility and the distance to roads as crucial
variables distinguishing resting sites of supplied and non‐supplied bison. The results indicate
that European bison select their resting sites in areas of mosaic habitat structure providing
cover from disturbances with access to profitable natural forage grounds.
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