Pleistocene glacial cycles and physical barriers influence phylogeographic structure in Black-capped Chickadees (Poecile atricapillus), a widespread North American passerine

Canadian Journal of Zoology,Volume 96, Issue 12, Page 1366-1377, December 2018. The nonmigratory Black-capped Chickadee (Poecile atricapillus (Linnaeus, 1766)) has a continent-wide distribution extending across large parts of North America. To investigate the phylogeographic structure and verify possible refugia during the last glacial maximum, we sequenced a 678 bp region of the mitochondrial control region from 633 Black-capped Chickadees at 35 sites across North America and performed paleoecological distribution modeling. Two genetically distinct groups were found using multiple analyses: one in Newfoundland (Canada) and a widespread continental group, with additional substructure evident in western continental populations. While gene flow is low throughout the range, it is especially low in peripheral populations. The Newfoundland population has remained isolated from continental populations for at least 65  000 years and contains a number of fixed nucleotide differences. Within the continental populations, Black-capped Chickadees are subdivided into Pacific Coast, Alaska (USA), southeast Rockies, and main-northeast groups consistent with late Pleistocene vicariance events. Evidence of secondary cont act was identified between Pacific and main-northeast populations in northwest British Columbia (Canada) and between southeast Rockies and main-northeast groups in Montana (USA). Paleoecological distribution modeling predicted suitable habitat in Alaska, off the coast of Ne...
Source: Canadian Journal of Zoology - Category: Zoology Authors: Source Type: research