The changing diversity and distribution of dry forest passerine birds in northwestern Peru since the last ice age

Abstract

ABSTRACT The role of Quaternary glacial–interglacial intervals in shaping the diversity and distribution of Neotropical species has been the focus of considerable research. The Neotropics sustain the highest passerine diversity on Earth, but little is known about this region's historical biogeography based on fossils. To assess how passerine species were affected by Quaternary climate fluctuations, we identified 625 late Pleistocene fossils (individual fossilized bones) from the now arid and faunally depauperate Talara Tar Seeps in northwestern Peru. Of the 21 passerine species identified, only 2 likely live at the site now; the remaining 19 species require more mesic conditions. Species identified included members of the Thamnophilidae (antbirds), Melanopareiidae (crescentchests), Tyrannidae (flycatchers), Hirundinidae (swallows), Mimidae (mockingbirds), Thraupidae (seedeaters, “finches”), Emberizidae (sparrows), and Icteridae (blackbirds). Nearly half of the individual fossils and 8 of the 21 species we...