title: Longspurs and snow buntings: phylogeny and biogeography of a high-latitude clade (Calcarius).
abstract: Using complete cytochrome b sequence data, we determined that the genus Calcarius, as presently recognized, is paraphyletic. Calcarius plus Plectrophenax form a highly supported clade composed of two subclades, a "snow bunting" clade comprised of Plectrophenax plus Calcarius mccownii (formerly in the monotypic genus Rhynchophanes), and a "collared" longspur clade of Calcarius lapponicus, ornatus, and pictus. Contrary to conventional thought, Calcarius is not phylogenetically close to either Calamospiza or Emberiza. Unlike these two genera, the taxonomic affinities of Calcarius appear to lie outside of the sparrow (tribe Emberizini) assemblage. Calcarius appears to be a relatively old songbird lineage, originating between 4.2 and 6.2 million years ago. Within Calcarius, pictus and ornatus form a closely related sister pair (2.9% divergent), as do Calcarius nivalis and hyperboreus (0.18% divergent). The group (Calcarius, sensu lato) is inferred to have its origins at relatively high latitudes in the New World.
authors.affiliation: J.F. Bell Museum of Natural History, 100 Ecology Building, University of Minnesota, St. Paul 55108-6097, USA. klicka@unlv.edu
authors.forename: John
authors.initials: J
authors.lastname: Klicka
authors.forename: Robert M
authors.initials: RM
authors.lastname: Zink
authors.forename: K
authors.initials: K
authors.lastname: Winker
mesh_terms: D000413:Alaska; D000818:Animals; D001110:Arctic Regions; D001483:Base Sequence; D003081:Cold Climate; D003573:Cytochrome b Group / Q000737:chemistry / Q000235:genetics; D017931:DNA Primers; D014644:Genetic Variation; D005843:Geography; D010802:Phylogeny; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D020308:Songbirds / Q000145:classification* / Q000235:genetics / Q000502:physiology; D013045:Species Specificity
chemical_list: D003573:Cytochrome b Group; D017931:DNA Primers