Pregled prilagajanja rabe prostora rjavega medveda (Ursus arctos) na antropogene motnje

Abstract

IZVLEČEKZa dolgoročno varstvo velikih zveri je pomembno razumevanje mehanizmov njihovega prilagajanja na prisotnost človeka, vključno z antropogenimi spremembami prostora. Rjavi medved (Ursus arctos) je za tovrstne raziskave zaradi holarktične razširjenosti in pojavljanja v različnih okoljih dobra modelna vrsta. S pregledom raziskav s celotnega območja razširjenosti vrste v svetu smo preučevali, kako medvedi prilagajajo rabo prostora intenziteti človekovih posegov v prostor. Medved se v splošnem antropogenim strukturam izogiba, še posebej stalno poseljenim območjem in močneje obremenjenim prometnicam. Zaznali smo tudi trend, da se medvedi na območjih z večjo gostoto prebivalstva pogosteje izogibajo antropogenim strukturam. Primerjava med Evropo in Severno Ameriko je nakazala večje izogibanje medvedov urbanim površinam v Evropi, pri drugih tipih antropogenih struktur pa so bile razlike med kontinentoma majhne. Pri primerjavi študij je vendarle potrebna previdnost, saj je večina obravnavanih raziskav temeljila na ugotavljanju relativne rabe prostora (t.j. raba glede na razpoložljivo), statistike absolutne rabe pa niso dovolj pogosto podane. Za ovrednotenje dejanske razlike v rabi prostora posameznih populacij medvedov iz okolij z različno stopnjo antropogenih motenj zato predlagamo analizo surovih podatkov.Ključne besede: Ursus arctos, rjavi medved, antropogeni dejavniki, vpliv človeka, posegi v prostor, gostota prebivalstva, prometnice, Evropa, Severna Amerika ABSTRACTFor successful large carnivore conservation it is important to understand mechanisms how large carnivores adapt to human presence, including anthropogenic environmental modifications. Widespread Holarctic distribution throughout various levels of human-use makes the brown bear (Ursus arctos) an appropriate model species for studying response to anthropogenic effects in large carnivores. We reviewed the literature throughout entire species' range to examine how bears modify their habitat use in response to the intensity of anthropogenic modifications of their environment. Results indicate that bears in general avoid human structures, with strongest avoidance observed for permanently inhabited areas and high-traffic roads. We observed their stronger avoidance of human structures in areas with higher human population densities. Comparison between Europe and North America indicate stronger avoidance of urban areas among European bears, while no obvious differences were observed for other types of anthropogenic infrastructure. We suggest caution when comparing responses among study areas, because most bear habitat-use studies reported only relative habitat selection (i.e. use relative to the availability) and there is lack of reported data on absolute habitat use. Therefore we recommend analysis of original data across the species' range in order to advance our understanding of bear habitat-use across a gradient of intensity of human disturbance.