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Please use this identifier to cite or link to this item:
http://hdl.handle.net/2282/332
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| Title: | Selective foraging on woody plant species by the Eurasian beaver (Castor fiber) in Telemark, Norway |
| Authors: | Haarberg, Orsolya
Rosell, Frank |
| Issue Date: | 2006 |
| Publishers version: | http://dx.doi.org/10.1111/j.1469-7998.2006.00142.x |
| Abstract: | Beavers Castor spp. are generalist herbivores, feeding on the bark, shoots and
leaves of woody plants, terrestrial herbs and forbs, ferns and aquatic vegetation.
As central-place foragers, beavers move out from water to select and cut trees and
vegetation, and then transport it back to their refuge. These terrestrial forays are
energetically costly; therefore, beavers should concentrate their foraging activity
near the central place and increase the degree of selectivity for specific sizes or
species of food with increasing distance from the water. The aim of this study was
to test the predictions of the central place and the optimal foraging theories for the
food selection of the Eurasian beaver Castor fiber, and show the foraging
preferences of the focal species in the boreal conifer forest zone of Europe.
Foraging intensity by beavers and the abundance of woody species were surveyed
in transects positioned randomly at seven beaver territories. In compliance with
the central-place foraging theory, the foraging intensity declined with increasing
distance from the river. Beavers fed preferentially on willows (Salix), rowan
(Sorbus) and birches (Betula), although alders (Alnus) dominated their diet. Size
selectivity showed similar patterns to previous North American studies, which
were also carried out in habitats with predominantly small saplings. The probability
of selection of small saplings dropped as distance increased, which is
consistent with the predictions of optimal foraging models that larger prey items
are more likely to be favoured with increasing provisioning distance. |
| Keywords: | Beavers
Foraging
Central-place foraging
Feeding preferences |
| Publisher: | Blackwell |
| Document type: | Journal article |
| URI: | http://hdl.handle.net/2282/332 |
| Appears in Collections: | Institutt for natur-, helse- og miljøvernfag
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