Breeding origins of a uniquely regular migrant songbird in the Galápagos Islands.

Autor: Perlut N; School of Marine and Environmental Programs University of New England Biddeford Maine USA., Maxwell LM; Department of Natural Resources and the Environment University of New Hampshire Durham New Hampshire USA., Kovach A; Department of Natural Resources and the Environment University of New Hampshire Durham New Hampshire USA., Parker P; Department of Biology University of Missouri - St. Louis St. Louis Missouri USA., Renfrew RB; Vermont Center for Ecostudies Norwich Vermont USA.
Jazyk: angličtina
Zdroj: Ecology and evolution [Ecol Evol] 2023 Jan 16; Vol. 13 (1), pp. e9697. Date of Electronic Publication: 2023 Jan 16 (Print Publication: 2023).
DOI: 10.1002/ece3.9697
Abstrakt: Little is known about the causes and consequences of alternative pathways flown by long-distance migratory birds. Bobolinks ( Dolichonyx oryzivorus ) breed in grasslands across northern North America and migrate from their breeding grounds toward the eastern Atlantic Coast and then proceed through the Caribbean to South America. However, a small but regular number of Bobolinks have been recorded on the Galapagos Islands. We collected genetic samples from nine Galapagos Bobolinks and performed double-digest restriction site-associated sequencing. We compared them with samples from seven locations across their breeding distribution to determine their population of origin. Galapagos Bobolinks shared the genetic structure of a cluster in the eastern portion of the breeding range that includes New Brunswick and Ontario, Canada, and Vermont, United States. Genetic assignment tests largely corroborated this finding, although slightly different results were obtained for the two methods. All individuals were assigned to the Ontario breeding population using AssignPop, while Rubias assigned six of the migrants to Ontario and three to a Midwest breeding population. Low average relatedness among Galapagos individuals indicates that they are not more related to one another than to individuals within a breeding population and are therefore likely not from a single, small isolated population. Our results do not support the probability hypothesis-that Galapagos Bobolinks originated from the region that includes the greatest proportion of their breeding range (Great Plains)-or the vagrant hypothesis-that migrants are displaced onto Galapagos due to weather events. Instead, our findings support the proximity hypothesis, where migrants originate from the geographically closest-breeding populations.
(© 2023 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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