Open AccessGenetic differentiation among populations of a migratory songbird: Limnothlypis swainsonii
Author(s) -
Winker Kevin,
Graves Gary R.,
Braun Michael J.
Publication year - 2000
Publication title -
journal of avian biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.022
H-Index - 76
eISSN - 1600-048X
pISSN - 0908-8857
DOI - 10.1034/j.1600-048x.2000.310307.x
Subject(s) - songbird , biology , gene flow , biological dispersal , population , subspecies , vicariance , warbler , range (aeronautics) , ecology , zoology , genetic structure , evolutionary biology , genetic variation , phylogeography , genetics , phylogenetic tree , gene , demography , habitat , materials science , sociology , composite material
Population structure and gene flow were inferred from isozyme variation at 26 loci among five populations of Limnothlypis swainsonii (Swainson's Warbler; Parulidae), a Nearctic‐Neotropic migrant songbird breeding in the unglaciated southeastern U.S.A. These populations exhibit relatively high levels of heterozygosity (=0.083), and 16 of 26 loci were polymorphic in at least one population (=0.385). Allelic frequencies were significantly heterogeneous at five loci, indicating a surprising degree of population structure for a migratory bird with no recognized subspecies ( F ST =0.043). Moderate levels of gene flow are inferred ( Nm =1.5 to 11.7), yet population structure does not fit an isolation‐by‐distance model. Genetic heterogeneity is mostly due to differentiation between an Arkansas population and four populations from the coastal plain (from Louisiana to Virginia). Genetic drift may be responsible for much of the observed structure, but the lack of obvious barriers to dispersal between Arkansas and the coastal plain suggests that differentiation has been maintained by some other mechanism(s). Vicariance events on the breeding range, a split wintering range, or both could contribute to the pattern of differentiation observed.