The Gray Fox Project

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Gray foxes in the Midwest United States: An impending extirpation in our own backyards

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Gray fox (Urocyon cinereoargenteus) numbers have declined precipitously in Ohio, as well as other states in the Midwestern United States. We hypothesize that gray foxes declined in number because of the co-occurrence of the invasion of coyotes (Canis latrans) as competitors, increase of raccoons (Procyon lotor) as sources of disease (particularly canine distemper), and a record-high harvest of gray foxes in the early 1980s (nearly 30,000 pelts sold in Ohio) because of high pelt prices. These factors occurred nearly simultaneously and may have synergistically served as a perfect storm to reduce gray fox populations below a critical point where inbreeding began to occur. In evidence of this, in 2015, 14 gray foxes were radiocollared, of which 11 died in less than 1 year. Two were struck by vehicles, six foxes died of disease (primarily canine distemper), and three died of massive infections originating from minor trap-related injuries. These three deaths of seemingly healthy foxes were troubling, and initially raised the possibility of the loss of immunity potentially arising from an inbreeding depression. Thus, we hypothesize that due to the initial decline in gray foxes, a resulting inbreeding depression has lowered fox immunity, decreasing survivorship even further. To test this hypothesis, DNA will be examined to seek evidence for a lack of genetic diversity, the consequences of which might also include smaller litters, increased pup mortality, and the potential expression of deleterious (harmful) recessive genes. We will also document the distribution and relative abundance of gray foxes in Ohio, as well as the severity of their decline across the Midwest.