Genetic structure, diversity, and interisland dispersal in the endangered Mariana Common Moorhen (Gallinula chloropus guami)

The Condor
By: , and 

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Abstract

The Mariana Common Moorhen (Gallinula chloropus guami) is a highly endangered taxon, with fewer than 300 individuals estimated to occur in the wild. The subspecies is believed to have undergone population declines attributable to loss of wetland habitats on its native islands in the Mariana Islands. We analyzed mitochondrial DNA (mtDNA) sequences (control region and ND2 genes) and nuclear microsatellite loci in Mariana Common Moorhens from Guam and Saipan, the two most distal islands inhabited by the subspecies. Our analyses revealed similar nuclear genetic diversity and effective population size estimates on Saipan and Guam. Birds from Guam and Saipan were genetically differentiated (microsatellites: FST = 0.152; control region: FST = 0.736; ND2: FST= 0.390); however, assignment tests revealed the presence of first-generation dispersers from Guam onto Saipan (1 of 27 sampled birds) and from Saipan onto Guam (2 of 28 sampled birds), suggesting the capability for long-distance interpopulation movements within the subspecies. The observed dispersal rate was consistent with long-term estimates of effective numbers of migrants per generation between islands, indicating that movement between islands has been an ongoing process in this system. Despite known population declines, bottleneck tests revealed no signature of historical bottleneck events, suggesting that the magnitude of past population declines may have been comparatively small relative to the severity of declines that can be detected using genetic data.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Genetic structure, diversity, and interisland dispersal in the endangered Mariana Common Moorhen (Gallinula chloropus guami)
Series title The Condor
DOI 10.1650/CONDOR-15-42.1
Volume 117
Issue 4
Year Published 2015
Language English
Publisher Cooper Ornithological Society
Contributing office(s) Forest and Rangeland Ecosystem Science Center, Contaminant Biology Program
Description 10 p.
First page 660
Last page 669
Country Guam, Saipan
Online Only (Y/N) N
Additional Online Files (Y/N) N