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Licensed Unlicensed Requires Authentication Published by De Gruyter March 16, 2016

Eastern fox squirrel (Sciurus niger, Linnaeus 1758) introduction to the Sonoran Desert

  • Matthew J. Brady EMAIL logo , John L. Koprowski , R. Nathan Gwinn , Yeong-Seok Jo and Kevin Young
From the journal Mammalia


The eastern fox squirrel, native to the eastern and midwestern United States, was recently documented in the Sonoran Desert in the vicinity of Yuma, Arizona, constituting the first state record for this species. We surveyed the people of Yuma to determine when and how the squirrels arrived. The squirrels were first observed in the 1960s, but may have been resident for a longer period. Since the 1960s, squirrels have spread throughout the city limits and extended south ~15 km into Somerton, Arizona. How the squirrels arrived is not clear, but must be the result of an introduction, as no nearby populations exist. The persistence of eastern fox squirrels in this unique habitat is due to synanthropic relationships.

Corresponding author: Matthew J. Brady, Division of Natural Sciences and Mathematics, Lewis-Clark State College, 500 8th Ave., Lewiston, ID 83501, USA, e-mail:


We would like to thank Melissa Merrick for the distribution map. Lin Piest, Arizona Department of Fish and Game, provided enthusiasm and insight in the early stages by making us aware of fox squirrels in the area. We would also like to thank all the participants of the online survey, whose input was invaluable to filling in some of the missing pieces to the timeframe of introduction, and Blake Herzog, reporter for the Yuma Sun newspaper, for working with us on the article that ran in the newspaper to solicit information from the public.


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Received: 2015-10-9
Accepted: 2016-1-20
Published Online: 2016-3-16
Published in Print: 2017-3-1

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