The hunting habitats of Goshawks Accipiter gentilis in boreal forests of central Sweden

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Abstract

Radio-tracking was used to study the habitat utilization of hunting Goshawks Accipiter gentilis in central Swedish boreal forest. Data were collected during September-June, in 1977–1981. There was no major difference between autumn, winter or spring in any aspect of habitat preference, despite seasonal differences in prey composition. Despite the strong reversed sexual size-dimorphism, no habitat segregation between the sexes was found. It is argued that this is due to the lack of prey segregation between the sexes. Goshawks showed a strong preference for mature forest, which was chosen twice as often as would be expected from its prevalence in the environment, whereas the younger successional stages of the forest were under-used. Goshawks preferred large habitat patches, and showed no major preference with respect to tree species composition of the forest. Kills made by radio-tagged Goshawks showed the same habitat- and patch-size distribution as did Goshawk locations in general. It is argued that the profitability of different hunting habitats, and thus habitat preferences, is not only determined by prey density in the habitats, but also by other habitat features influencing the Goshawk's ability to hunt there. Winter home-ranges averaged 5700 ha, considerably larger than Goshawk ranges recorded in areas with richer prey supply.

Ancillary