Wolf number changes in Bieszczady National Park, Poland

From 1991 to 1995, wolf Canis lupus (Linnaeus, 1758) population dynamics were studied in Bieszczady National Park and the surrounding area (520 km(2)). The study area was utilized by 5 packs. Pack sizes averaged 5.6 in early and 3.9 in late winter. Overwinter declines in wolf numbers ranged from 21% to 39% ((x) over bar = 29%), which corresponded well to the known number of wolves killed by hunters or dead of other causes. After every winter decline, wolf numbers recovered through reproduction. Generally, wolf numbers were stable or slightly decreasing during the study. Three neighbouring wolf packs occupied an area of 340 km(2) and the estimated territory size averaged 85 km(2). The estimated density of wolves averaged 5.1/100 km(2) in early winter and 3.3/100 km(2) in late winter. Of all known causes of wolf mortality, 86% were from legal hunting, 5% were from poaching, and 9% were from natural causes. Bieszczady National Park is small in size and its topography influences the spatial distribution of packs. No single pack was fully contained within, or protected by the Park. The number of wolves is overestimated in official reports, because the same packs are likely counted as different groups in neighbouring census units. On hunting grounds adjacent to Bieszczady NP, harvest plans exceed the actual number of wolves which inhabit the area. The creation of a wolf protection zone around Bieszczady NP and some regulations for wolf management in the rest of the region are proposed.