title: Home-range use patterns and movements of the Siberian flying squirrel in urban forests: Effects of habitat composition and connectivity.
abstract: BACKGROUND
  Urbanization causes modification, fragmentation and loss of native habitats. Such landscape changes threaten many arboreal and gliding mammals by limiting their movements through treeless parts of a landscape and by making the landscape surrounding suitable habitat patches more inhospitable. Here, we investigate the effects of landscape structure and habitat availability on the home-range use and movement patterns of the Siberian flying squirrel (Pteromys volans) at different spatial and temporal scales. We followed radio-tagged individuals in a partly urbanized study area in Eastern Finland, and analysed how landscape composition and connectivity affected the length and speed of movement bursts, distances moved during one night, and habitat and nest-site use.
  
  
  RESULTS
  The presence of urban habitat on movement paths increased both movement lengths and speed whereas nightly distances travelled by males decreased with increasing amount of urban habitat within the home range. The probability of switching from the present nest site to another nest site decreased with increasing distance among the nest sites, but whether the nest sites were connected or unconnected by forests did not have a clear effect on nest switching. Flying squirrels preferred to use mature forests for their movements at night.
  
  
  CONCLUSIONS
  Our results suggest that the proximity to urban habitats modifies animal movements, possibly because animals try to avoid such habitats by moving faster through them. Urbanization at the scale of an entire home range can restrict their movements. Thus, maintaining a large enough amount of mature forests around inhabited landscape fragments will help protect forest specialists in urban landscapes. The effect of forested connections remains unclear, highlighting the difficulty of measuring and preserving connectivity in a species-specific way.
authors.affiliation: Finnish Museum of Natural History LUOMUS, University of Helsinki, P. O. Box 17 (P. Rautatiekatu 13), Helsinki, FI-00014 Finland.
authors.forename: Sanna
authors.initials: S
authors.lastname: Mäkeläinen
authors.affiliation: Department of Biosciences, University of Helsinki, P. O. Box 65 (Viikinkaari 1), FI-00014 Helsinki, Finland ; Current address: Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, Wageningen, 6708 PB The Netherlands.
authors.forename: Henrik J
authors.initials: HJ
authors.lastname: de Knegt
authors.affiliation: Department of Biosciences, University of Helsinki, P. O. Box 65 (Viikinkaari 1), FI-00014 Helsinki, Finland.
authors.forename: Otso
authors.initials: O
authors.lastname: Ovaskainen
authors.affiliation: Finnish Museum of Natural History LUOMUS, University of Helsinki, P. O. Box 17 (P. Rautatiekatu 13), Helsinki, FI-00014 Finland.
authors.forename: Ilpo K
authors.initials: IK
authors.lastname: Hanski
keywords: Connectivity; Habitat fragmentation; Home range; Movements; Nest-site use; Siberian flying squirrel; Urbanization