Diversifying Coevolution between Crossbills and Conifers

22Citations
Citations of this article
111Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

Coevolution between granivorous crossbills (Loxia spp.) and conifers has been a prominent process in the diversification of crossbills. A striking example occurs in western North America where coevolution between crossbills and Rocky Mountain lodgepole pine (Pinus contorta latifolia) is ongoing in isolated ranges without the crossbill's dominant competitor for seeds, the red squirrel (Tamiasciurus hudsonicus). Preferential foraging by crossbills on lodgepole pine cones in the South Hills and Albion Mountains, two small mountain ranges in southern Idaho where red squirrels are absent, has led to the evolution of larger, thicker-scaled cones than in nearby ranges where red squirrels are present. This in turn has favored the evolution of larger-billed crossbills that have diverged from other crossbills in the region. However, such diversifying coevolution, resulting from geographic variation in the distribution of strongly interacting species, is vulnerable to species introductions. For example, the introduction of red squirrels caused the precipitous decline and perhaps extinction of the Newfoundland crossbill and perhaps a crossbill endemic to the Cypress Hills, Canada. In general, species introductions act to reduce the geographic variation in species interactions, which may be critical for the diversification of many taxa.

Cite

CITATION STYLE

APA

Benkman, C. W. (2010). Diversifying Coevolution between Crossbills and Conifers. Evolution: Education and Outreach, 3(1), 47–53. https://doi.org/10.1007/s12052-009-0190-8

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free