Continental phylogeography of an ecologically and morphologically diverse Neotropical songbird, Zonotrichia capensis

Abstract

BackgroundThe Neotropics are exceptionally diverse, containing roughly one third of all extant bird species on Earth. This remarkable species richness is thought to be a consequence of processes associated with both Andean orogenesis throughout the Tertiary, and climatic fluctuations during the Quaternary. Phylogeographic studies allow insights into how such events might have influenced evolutionary trajectories of species and ultimately contribute to a better understanding of speciation. Studies on continentally distributed species are of particular interest because different populations of such taxa may show genetic signatures of events that impacted the continent-wide biota. Here we evaluate the genealogical history of one of the world’s most broadly-distributed and polytypic passerines, the rufous-collared sparrow (Zonotrichia capensis).ResultsWe obtained control region DNA sequences from 92 Zonotrichia capensis individuals sampled across the species’ range (Central and South America). Six additional molecular markers, both nuclear and mitochondrial, were sequenced for a subset of individuals with divergent control region haplotypes. Median-joining network analysis, and Bayesian and maximum parsimony phylogenetic analyses all recovered three lineages: one spanning Middle America, the Dominican Republic, and north-western South America; one encompassing the Dominican Republic, Roraima (Venezuela) and La Paz (Bolivia) south to Tierra del Fuego, Argentina; and a third, including eastern Argentina and Brazil. Phylogenetic analyses suggest that the Middle American/north-western South American clade is sister to the remaining two. Bayesian and maximum likelihood coalescent simulations used to study lineage demographic history, diversification times, migration rates and population expansion together suggested that diversification of the three lineages occurred rapidly during the Pleistocene, with negligible gene flow, leaving genetic signatures of population expansions.ConclusionsThe Pleistocene history of the rufous-collared sparrow involved extensive range expansion from a probable Central American origin. Its remarkable morphological and behavioral diversity probably represents recent responses to local conditions overlying deeper patterns of lineage diversity, which are themselves produced by isolation and the history of colonization of South America.

Why are tropical mountain passes “low” for some species? Genetic and stable‐isotope tests for differentiation, migration and expansion in elevational generalist songbirds

“…Considering the physical landscape of the western Andes, this expansion likely originated in high‐elevation environments that are diverse and productive relative to dry coastal zones that are depauperate and may have fewer competitors. Published phylogenies for tanagers (including C. cinereum ) (Burns et al., ), siskins (including S. magellanicus ) (Beckman & Witt, ), South American T. aedon populations (Galen & Witt, ; Galen et al., ) and Z. capensis populations (Lougheed et al., ) are all consistent with montane origins and subsequent, downslope range expansions in western Peru. As a caveat, it should be noted that false inference of population expansion from mtDNA haplotype frequency spectra can be caused by other demographic events, such as selective sweeps (Fay & Wu, ; Przeworski, ; Wakeley & Aliacar, ).…”

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“…The mitochondrial uncorrected pairwise distance between the two species is also relatively small (0.3-0.8%), consistent with a very recent speciation event. This pattern of closely related species on either side of the Andes has been documented in several other cases of birds (Brumfield and Capparella 1996, Miller et al 2008, Weir and Price 2011, Lougheed et al 2013. Some of these instances were shown to be the probable result of trans-Andean gene flow (Miller et al 2008), but this seems unlikely with ground doves given their poor long-distance flight ability.…”

First genetic assessment of the level of endemism in the avifauna of the Central Sierras in southern South America

“…All these subspecies have been proposed based on morphological measures and plumage color (Heinroth , Höy , Nores and Yzurieta , , ), but none of them has been evaluated using molecular markers yet. The study of morphology‐based subspecific designations using genetic information often shows a lack of correspondence between these designations and intraspecific evolutionary history (Zink , Lougheed et al ). Even though sometimes subspecies do represent lineages evolving independently (Masello et al , Campagna et al , Fernandes et al ) it is common to find that there are many more subspecies than divergent lineages in Neotropical avian taxa (Zink , Miller et al , Campagna et al , , Lavinia et al ).…”