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We characterized the pattern and magnitude of phylogeographical variation among breeding populations of a long-distance migratory bird, the Wilson's warbler (Wilsonia pusilla), and used this information to assess the utility of mtDNA markers for assaying demographic connectivity between breeding and overwintering regions. We found a complex pattern of(More)
In this paper, we address alternative hypotheses for the evolution of subspecies of rock ptarmigan (Lagopus mutus) endemic to the Aleutian Archipelago. To do this we examined patterns of genetic differentiation among populations of rock ptarmigan in the Aleutian Islands and parts of both Alaska and Siberia. Variation in mitochondrial control region(More)
The glacial refugium hypothesis (GRH) proposes that glaciers promoted differentiation and generation of intraspecific diversity by isolating populations in ice-free refugia. We tested three predictions of this hypothesis for the evolutionary divergence of rock ptarmigan (Lagopus mutus) during the Wisconsin glaciation of the late Pleistocene. To do this, we(More)
Hypotheses for divergence and speciation in rainforests generally fall into two categories: those emphasizing the role of geographic isolation and those emphasizing the role of divergent selection along gradients. While a majority of studies have attempted to infer mechanisms based on the pattern of species richness and congruence of geographic boundaries,(More)
Certain predictions of optimal- and central place-foraging theory were tested on the desert harvester ant, Pogonomyrmex californicus. Colonies were offered three different sizes of oat seed and found to maximize net energy intake (ei) over time (t i ) by harvesting the seed sizes with the highest e i /t i rank. Two aspects of t i were measured that were(More)
Hypotheses for divergence and speciation in rainforests generally fall into two categories: those emphasizing the role of geographic isolation and those emphasizing the role of divergent selection along gradients. While a majority of studies have attempted to infer mechanisms based on the pattern of species richness and congruence of geographic boundaries,(More)
We illustrate the use of Faith's 'Phylogenetic Diversity' measure to compare the phylogeographic structure of two bird species with patterns of avian endemism across six mountains in Cameroon and Equatorial Guinea. The Mountain Greenbul and Cameroon Blue-headed Sunbird showed phylogeographic patterns that together defined three biogeographic regions: Bioko,(More)
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