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Data from: Matching habitat choice in nomadic crossbills appears most pronounced when food is most limiting

Citation

Benkman, Craig W. (2016), Data from: Matching habitat choice in nomadic crossbills appears most pronounced when food is most limiting, Dryad, Dataset, https://doi.org/10.5061/dryad.dg41r

Abstract

Of the various forms of non-random dispersal, matching habitat choice, whereby individuals preferentially reside in habitats where they are best adapted, has relatively little empirical support. Here I use mark-recapture data to test for matching habitat choice in two nomadic ecotypes of North American Red Crossbills (Loxia curvirostra complex) that occur in the lodgepole pine (Pinus contorta) forests in the South Hills, Idaho every summer. Crossbills are adapted for foraging on seeds in conifer cones, and in the South Hills the cones are distinctive, favoring a relatively large bill. During a period when seed was most limiting, only the largest individuals approximating the average size of the locally adapted ecotype remained for a year or more. During a period when seed was less limiting, proportionately more individuals remained and the trend for larger individuals to remain was weaker. Although matching habitat choice is difficult to demonstrate, it likely contributed to the observed patterns. Otherwise, nearly unprecedented intensities of natural selection would be needed. Given the nomadic behavior of most crossbill ecotypes and the heterogeneous nature of conifer seed crops, matching habitat choice should be favored and likely contributes to their adaptation to alternative conifers and rapid diversification.

Usage Notes

Location

USA
South Hills
Idaho