Long-term isolation of a highly mobile seabird on the Galapagos

Proceedings of the Royal Society B: Biological Sciences
By: , and 

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Abstract

The Galapagos Islands are renowned for their high degree of endemism. Marine taxa inhabiting the archipelago might be expected to be an exception, because of their utilization of pelagic habitats--the dispersal barrier for terrestrial taxa--as foraging grounds. Magnificent frigatebirds (Fregata magnificens) have a highly vagile lifestyle and wide geographical distribution around the South and Central American coasts. Given the potentially high levels of gene flow among populations, the species provides a good test of the effectiveness of the Galapagos ecosystem in isolating populations of highly dispersive marine species. We studied patterns of genetic (mitochondrial DNA, microsatellites and nuclear introns) and morphological variation across the distribution of magnificent frigatebirds. Concordant with predictions from life-history traits, we found signatures of extensive gene flow over most of the range, even across the Isthmus of Panama, which is a major barrier to gene flow in other tropical seabirds. In contrast, individuals from the Galapagos were strongly differentiated from all conspecifics, and have probably been isolated for several hundred thousand years. Our finding is a powerful testimony to the evolutionary uniqueness of the taxa inhabiting the Galapagos archipelago and its associated marine ecosystems.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Long-term isolation of a highly mobile seabird on the Galapagos
Series title Proceedings of the Royal Society B: Biological Sciences
Volume 278
Issue 1707
Year Published 2011
Language English
Publisher Royal Society Publishing
Publisher location London, England
Contributing office(s) Patuxent Wildlife Research Center
Description 9 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Proceedings of the Royal Society B: Biological Sciences
First page 817
Last page 825
Country Ecuador
Other Geospatial Galapagos Islands