Multiple introductions of the eastern fox squirrel (Sciurus niger) in California

Abstract

Eastern fox squirrels (Sciurus niger) have been introduced into California within the past 130 years. Recently, their range has been expanding at an alarming rate. Genetic diversity was assessed in 101 control region sequences of eastern fox squirrels from three geographic regions within California (Los Angeles County, Alameda and Contra Costa counties and Sacramento County) to determine if a single or multiple introductions occurred within California, as indicated by the detection of multiple haplotypes. A total of 11 haplotypes were discovered, with haplotypes rarely shared among geographic regions and no clustering by region in a haplotype network. This suggests that the introduction to different regions within California came from different source populations within the native range of the species. Haplotype diversity was highest in Los Angeles County. Due to a lack of phylogeographic structure in fox squirrels in their native range, it is difficult to identify the sources of all introductions.

• Control region
• fox squirrels
• introduced species
• Sciurus niger

Acknowledgements

The authors thank the California Wildlife Center, Pasadena Humane Society, South Bay Wildlife Rehab, Lindsay Wildlife Museum, Sulfur Creek Nature Center and USDA APHIS California Wildlife Services for providing samples of eastern fox squirrels used in this study.

Declaration of interest

The work was supported by a grant from the National Institute of General Medical Sciences of the National Institutes of Health RISE GM61331. The authors report no conflicts of interest and are responsible for the content and writing of the paper.