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Site Fidelity Is an Inconsistent Determinant of Population Structure in the Hooded Merganser (Lophodytes cucull atus): Evidence from Genetic, Mark–Recapture, and Comparative Data

TitleSite Fidelity Is an Inconsistent Determinant of Population Structure in the Hooded Merganser (Lophodytes cucull atus): Evidence from Genetic, Mark–Recapture, and Comparative Data
Publication TypeJournal Article
Year of Publication2008
AuthorsPearce, JM, Blums, P, Lindberg, MS
JournalThe Auk
Volume125
Pagination711–72522
Abstract

The level of site fidelity in birds is often characterized as ‘‘high’’ on the basis of rates of return or homing frommark–recapture data. For species that exhibit site fidelity, subsequent biological assumptions have included population structure,demographic independence, and that the extirpation of a site-faithful group might be irreversible because of low immigration. Yet severalgenetic studies have observed patterns of population differentiation that are incongruous with strong site fidelity, which suggestsrecent isolation, gene flow, or both. Using a 13-year live-recapture and dead-recovery data set, as well as nuclear and mitochondrial DNAcollected across the range of the Hooded Merganser (Lophodytes cucullatus), an obligate cavity-nester endemic to North America, wefound evidence that gene flow persists across portions of the species’ range even though the probability of female breeding-site fidelity ishigh (0.92; 95% confidence interval [CI]: 0.64–0.98) and disjunct breeding ranges of this species have been isolated for &\#8805;10,000 years. Bycombining inferences from genetic, band-recovery, mark–recapture, and comparative data from another cavity-nesting species of waterfowl,we conclude that a high level of site fidelity should not be considered a universal proxy for population structure and demographicindependence. Our results also suggest that an accurate assessment of site fidelity–-and its implications for population dynamics anddelineation–-requires cross-species comparisons and multiple data types, such as mark–recapture and genetic information, to best inferpatterns across a range of geographic and temporal scales

DOI10.1525/auk.2008.07154
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