Inactivity/sleep in two wild free-roaming African elephant matriarchs – Does large body size make elephants the shortest mammalian sleepers?

• Nadine Gravett,

  Affiliation School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

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• Adhil Bhagwandin,

  Affiliation School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

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• Robert Sutcliffe,

  Affiliation Elephants Without Borders, Kasane, Botswana

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• Kelly Landen,

  Affiliation Elephants Without Borders, Kasane, Botswana

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• Michael J. Chase,

  Affiliation Elephants Without Borders, Kasane, Botswana

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• Oleg I. Lyamin,

  Affiliation Department of Psychiatry, University of California, Los Angeles, Neurobiology Research 151A3, Sepulveda VAMC, North Hills, California, United States of America

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• Jerome M. Siegel,

  Affiliation Department of Psychiatry, University of California, Los Angeles, Neurobiology Research 151A3, Sepulveda VAMC, North Hills, California, United States of America

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• Paul R. Manger

  * E-mail: Paul.Manger@wits.ac.za

  Affiliation School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

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