The Pleistocene Zhoukoudian ‘Peking Man’ site records the first Beijing (China) evidence of the Northern Raven (Corvus corax)

Analyses of fossil mammal faunas from 2945 localities in the United States demonstrate that the geographic ranges of individual species shifted at different times, in different directions, and at different rates in response to late Quaternary environmental fluctuations. The geographic pattern of faunal provinces was similar for the late Pleistocene and late Holocene, but differing environmental gradients resulted in dissimilar species composition for these biogeographic regions. Modern community patterns emerged only in the last few thousand years, and many late Pleistocene communities do not have modern analogs. Faunal heterogeneity was greater in the late Pleistocene.

Significance Over the past half century, populations of neotropical migratory birds in North America have plummeted while populations of resident species have largely remained stable. We show that resident and migratory birds in eastern North America have responded differently to climate change over this period, with the ranges of resident species expanding along their northern margin while the ranges of migratory species have contracted at their southern margin. These results suggest that the ability to colonize newly suitable areas may make resident species resilient to future climate change but that climate-induced range contractions may make neotropical migrants vulnerable to these changes.