Noam Leader, Eli Geffen, Ofer Mokady and Yoram Yom-Tov (2008): Song dialects
do not restrict gene flow in an urban population of the orange-tufted
sunbird, Nectarinia osea. Behav. Ecol. Sociobiol. 62(8), 1299-1305.
Abstract: Geographic variation in vocalizations is widespread in passerine
birds, but its origins and maintenance remain unclear. In this study, we
test the hypothesis that song dialect, a culturally transmitted trait, is
related to the population genetic structure of the orange-tufted sunbird,
Nectarinia osea. To address this, we compared mitochondrial DNA (mtDNA)
sequence variation together with allele frequencies at five microsatellite
loci from an urban population of sunbirds exhibiting two distinct song
dialects on a microgeographic scale. Our findings reveal no association
between dialect membership and genetic composition. All genetic measures,
from both mitochondrial and nuclear DNA, indicate high levels of gene flow
between both dialect populations. The low F ST values obtained from mtDNA
and microsatellite analysis imply that the variation among dialects does not
account for more than 2%, at best, of the overall genetic variation found in
the entire population. These measures fall well within the range of similar
measures obtained in other studies of species exhibiting vocal dialects,
most of which fail to detect any dialect-based genetic differentiation. The
persistence of dialects in the orange-tufted sunbird may thus best be
explained by dispersal of individuals across dialect boundaries and possibly
from surrounding areas, followed by postdispersal vocal matching. Because
genetic structuring appears weaker than cultural structure in this species,
we discuss the behavioral mechanisms underlying dialect maintenance in the
presence of apparent gene flow.
URL: http://www.springerlink.com/content/x3n2898227302m63/
For reprints please contact Noam Leader (Email:
Kind regards
Sonja
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