Prey selection and predation by wolves in Bialowieza Primeval Forest, Poland

Relationships of wolves (Canis lupus) and ungulates were studied in the Pol ish part of Bialowieza Primeval Forest with high densities of prey. The num ber of wolves ranged from 7 to 19, and the number of packs ranged from 2 to 4. Average densities were 2.3 wolves/100 km(2). Red deer (Cervus elaphus) was the main prey of wolves. Roe deer (Capreolus capreolus), wild boar (Sus scrofa), moose (Alces alces), and European bison (Bison bonasus) were hunt ed less than expected based on their abundance. Mean mass of ungulates kill ed by wolves was 55 kg. Prey were consumed quickly, with 57% of kills compl etely eaten on the Ist day after killing. Average killing rate by wolves wa s 0.78 ungulate per wolf pack per day (0.14 prey item per wolf per day). Re sults of this study combined with the data obtained in the Belarussian part of Bialowieza Primeval Forest in 1946-1985 allowed for analysis of dietary response of wolves to changes in densities of ungulates. Wolves showed a r esponse to abundance of red deer. The amount of other ungulates in their di et depended on the densities of red deer. From 1991 to 1996, wolves annuall y removed 57-105 red deer, 19-38 wild boar, 19-25 roe deer, and 0-2 moose p er 100 km(2). Those amounts were equivalent to 9-13% of spring-summer densi ties of red deer, 4-8% of wild boar, 3-4% of roe deer, and 0-29% of moose. Additionally, hunters annually harvested 131-140 red deer, 44-114 roe deer, 1-7 moose, and 45-142 wild boar per 100 km(2). Effects of predation and ha rvest by hunters on ungulate mortality were likely additive and caused decl ines in ungulate populations during our study.