Intake Rate Maximization and the Foraging Behaviour of Crossbills

Publication Type:Journal Article
Year of Publication:1989
Authors:Benkman, CW
Journal:Ornis Scandinavica
Date Published:1989
ISBN Number:00305693
Keywords:Fringillidae, Loxia, Loxia curvirostra, Loxia leucoptera
Abstract:Foraging Two-barred Crossbills Loxia leucoptera remove seeds first from the basal scales of tamarack cones, then proceed to the distal end. Seeds, however, are often left in the distal-most scales. To determine if crossbill cone-leaving behaviour maximized intake rates, seed kernels were weighed from the different cone scales and the foraging behaviour of crossbills was quantified. Crossbills usually removed seeds from one scale more than that which would have maximized intake rates. Nevertheless, this behaviour provided an intake rate that nearly equaled the maximum. Crossbills appear to use a cone-leaving rule of "leave when kernel mass declines".
Short Title:Ornis Scandinavica
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