Insularity and the determinants of lizard population density

Authors: Buckley, Lauren B.; Jetz, Walter

Source: Ecology Letters, Volume 10, Number 6, June 2007 , pp. 481-489(9)

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Abstract:

The relative effects of resource availability and partitioning on animal population density are unresolved yet central to ecology and conservation. Species-depauperate islands offer an intriguing test case. Across 643 lizard populations from around the world, local abundances are one order of magnitude higher on islands than on mainlands, even when controlled for resource availability. On mainlands, predator and competitor richness only weakly correlate with lizard densities. On islands, sharp reductions in predator and competitor richness are the dominant drivers of lizard abundance. Our results demonstrate the dramatic effect insularity has on the interplay between biotic and abiotic control of animal abundances and the heightened sensitivity of island communities to species' losses and gains.

Keywords: Competition; density compensation; ecological release; energetic constraints; islands; lizards; population density; predation

Document Type: Research article

DOI: http://dx.doi.org/10.1111/j.1461-0248.2007.01042.x

Affiliations: 1: Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA

Publication date: 2007-06-01