PREDATION OF EURASIAN LYNX ON ROE DEER AND RED DEER IN BIALOWIEZA PRIMEVAL FOREST, POLAND

Patterns of lynx Lynx lynx (Linnaeus, 1758) predation on ungulates wer e studied in the Polish part of Bialowieza Primeval Forest (580 km(2)) from seats and prey remains of lynx between 1985-1996, and radiotrack ing of 18 lynx between 1991-1996. Cervids were the main prey and const ituted 90% of food biomass consumed (analysis of faeces) and 84% of pr ey killed. Roe deer Capreolus capreolus was positively selected by all lynx (though stronger by females and subadults than by adult males). Fawns and adult roe deer of both sexes were preyed on in proportion to their abundance in the population. Red deer Cervus elaphus was taken less often than would have been expected at random, and fawns were pos itively selected by lynx. On average, lynx spent 76 h (3.2 days) feedi ng on a killed deer (from 38 h in a female with 3 kittens to 105 h in single adult females). Mean searching time (ie time from leaving the r emains of one deer to killing another one) was 52 h (2.2 days); from 1 0 h in a female with 3 young to 104 h in subadults. Thus, the average kill rate by lynx was one deer per 5.4 days. Predation impact of lynx population on roe and red deer was estimated in 1991-1996, when record ed numbers were 288-492 roe deer and 359-607 red deer per 100 km(2) in late winter (March), and 501-820 roe deer and 514-858 red deer per 10 0 km(2) in spring (May/June). During that period densities of deer dec lined markedly due to deliberately elevated hunting harvest by forestr y personnel, aimed at reduction of game damage to silviculture. Densit ies of adult lynx were little variable (2.4-3.2 inds/100 km(2)), but r eproduction rate strongly varied in response to deer decline, from 0.6 7 juv/adult lynx in 1991/92 to 0.25 juv/adult lynx in 1995/96. Annuall y, lynx population killed 110-169 roe deer/100 km(2), which constitute d 21-36% of spring (seasonally highest) numbers of roe deer. Lynx pred ation was the most important factor of roe deer mortality. Furthermore , lynx population took 42-70 red deer/100 km(2) annually, which consti tuted 6-13% of spring number of red deer. In red deer mortality, lynx predation played an inferior role to hunting harvest and wolf predatio n.