6533b830fe1ef96bd1296f51

RESEARCH PRODUCT

Effects of fragmented breeding habitat and resource distribution on behavior and survival of the bank vole ( Myodes glareolus )

subject

description

Habitat fragmentation causes negative population trends or even local extinction in many species. Understanding the role of fragmentation on behavior and space use of animals is an essential part of revealing the mechanism behind observed population declines. We studied experimentally the effects of small-scale habitat fragmentation on the distribution and movement of bank voles (Myodes glareolus) in seminatural enclosures. We predicted that besides habitat structure, availability of two resources, food for both sexes, and receptive females for males, determine individual distribution. We manipulated female density (either 0, 4, or 12 per enclosure) and followed movements of radio-collared males. We also studied the effect of unequal food distribution between the fragments on vole distribution. The habitat of 0.25-ha enclosures was manipulated by forming either one large, two medium-sized, or four small habitat patches surrounded by an inhospitable matrix. Female density and distribution clearly affected male spacing behavior. Males had larger home ranges in the medium female density enclosures. Furthermore, the use of the inhospitable and risky matrix area increased with habitat fragmentation. Food supplementation improved individual condition measured as body mass but did not affect breeding success. Our experiments demonstrated that both small-scale habitat fragmentation and resource distribution affect the behavior and condition of individuals. Increased fragmentation led to increased risk taking in both mating and foraging behavior. This should have direct survival and fitness consequences, and therefore our results may be extrapolated to population-level consequences of habitat fragmentation.