From 1983–2001, nest and chick losses in capercaillie and hazel grouse were studied in the mountains of Central Slovakia (Veľká Fatra Mts, Malá Fatra Mts, Kremnické vrchy Mts, Starohorské vrchy Mts, and Nízke Tatry Mts, 18°50’–19°10’E; 48°47’–49°19’N). Out of 75 capercaillie clutches 49 (65%) were destroyed. Out of 159 hazel grouse clutches 104 (65%) were destroyed. The main mammalian egg predators were stone marten (Martes foina), pine marten (Martes martes), mustelids (Mustela sp.), and red fox (Vulpes vulpes) (altogether 22%), wild boar (Sus scrofa) (9%), and brown bear (Ursus arctos) (3%). The predation pressure on capercaillie and hazel grouse nests decreased significantly during the incubation period (74% nest losses during the first half of May, 54% in the second half of May). Nest losses in both capercaillie and hazel grouse followed the fluctuation in small rodents, with lowest losses during peak year (57%) and highest losses during crash year (82%) and prepeak year (80%). Average number of capercaillie chicks accompanying a hen in June significantly decreased during the study period (5.0 in 1983, 2.6 in 2001). In contrast, in hazel grouse, no significant decrease in number of chicks per hen in June was recorded during the study period.
The food composition of the brown bear diet was studied on the basis of 215 excrement samples, which were collected in 2008-2010 in the area of the Eastern Carpathians (Poloniny National Park). The seasonal changes in food composition reflected the supply of the environment, which is nowadays influenced by human activities. This situation resulted in a stronger adaptation of bear to anthropogenic food sources of plant origin compared to historical data from the Carpathians. We identified diagnostic groups and food components consumed by bears in individual seasons of the evaluated period. In spring, crops provided by hunters were found to be
the diagnostic group; and corn, silage, rape, bark and wood were diagnostic components. In summer, invertebrates were the diagnostic group; and ants, cherries and grass were the diagnostic components. In autumn, fruit were the diagnostic group; and apples, pears, blackberries, plums and acorns were the diagnostic components. In winter, hard mast and crops provided by hunters were diagnostic groups; and beechnuts, sunflower, rape, wheat, corn and corn silage were diagnostic components. From the nutritional point of view, crops provided by hunters dominated in spring and summer, and hard mast dominated in autumn and winter.