How Many Kinds of Birds Are There and Why Does It Matter?

• George F. Barrowclough ,

  * E-mail: gfb@amnh.org

  Affiliation Department of Ornithology, American Museum of Natural History, New York, New York United States of America

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• Joel Cracraft,

  Affiliation Department of Ornithology, American Museum of Natural History, New York, New York United States of America

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• John Klicka,

  Affiliation Department of Biology and Burke Museum of Natural History and Culture, University of Washington, Seattle, Washington, United States of America

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• Robert M. Zink

  Affiliation School of Natural Resources, Nebraska State Museum, and School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America

  http://orcid.org/0000-0001-9243-4567

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