Epsilon Archive for Student Projects

Abstract

Habitat selection studies are important in increasing our understanding of population patterns and processes in fragmented and spatially heterogeneous landscapes. Identification and characterisation of a species' habitat requirements are essential in guiding land-use management practices aimed at the protection of critical habitats. With such knowledge we can understand animal ecology and achieve management practices to conserve species.
Serious declines in the population of Siberian jays Perisoreus infaustus have been observed in recent decades in parts of Fennoscandia. These population declines have been attributed to modern forestry altering habitat from native old spruce to pine plantations and habitat fragmentation.
Through radio-tracking 8 focal birds and habitat surveying I assessed jay habitat selection and elucidated their behavioural choices at multiple-scales during autumn and winter.
Jays strongly preferred forest and avoided wooded bogs and cutovers when moving along trajectories in the homerange. At this scale they preferred intermediate densities of large spruce and pine forest avoiding forest with no spruce or too dense pine. Furthermore, jays avoided young forest preferring older, closed canopy forest with an intermediate level of vertical structure. Small scale observations showed Siberian jays had a distinct preference for food searching in spruce avoiding pine and birch in this respect. Jays also preferred to sit in spruce trees, avoided birch and used pine randomly.
These results suggest that without adequate and well planned management of old growth spruce forest, forestry is likely to result in further declines in Siberian jays in northern Sweden.