Candid Canid

Thanks to an active Chicago Wildlife Watch user (@ForestPreserve), we were thrilled to be connected this week with a local Chicago-area resident who reported a sighting of an unknown canid (member of the dog family, Canidae) in his wooded backyard. Wilmette resident Jim Graham happened to snap this photo of the animal through his screen door on October 10, 2017, and sent it along to Lincoln Park Zoo's Urban Wildlife Institute team. As experts in identifying unknown animals from photos, we got right on the case!

After some light photo editing, we could hardly believe what we were seeing: this was, in fact, the elusive gray fox (Urocyon cinereoargenteus)!

Photo credit: Jim Graham

How did we come to this conclusion? The animal in this photo has some clear characteristics of a gray fox, including contrasting rust, white, and mottled gray markings, a long, black stripe along the length of its tail, and a cat-like head with a short snout. This photo shows all three of these characteristics, easily differentiating this canid from the red fox and coyote, species that are more frequently sighted in Chicago. A red fox would be much more vibrant red throughout its body, and a coyote would be larger, with a pointed, black-tipped tail, and less contrast in its markings.

Gray foxes typically prefer forested areas, forest edges, or shrub habitats, and although they may hunt in the daytime, they are typically nocturnal. They are omnivores, which mean that they eat a variety of foods, including small mammals (i.e., rabbits, mice), invertebrates, fruit, and nuts. Gray foxes are generally solitary, but pair up with mates during the breeding season, and both males and females raise young. A fun fact about gray foxes: they are the only canid species to climb trees! Because they are mainly forest dwellers, they likely use this adaptation to escape from predators.

Although gray foxes range widely throughout North America and northern South America, they appear to be declining in northern Illinois. Using trail cameras, we have been monitoring wildlife throughout the Chicago region at more than 100 sites since 2010. Throughout the study, we have only captured ONE photo of a gray fox, back in 2012 from Glenview:

And this photo of a gray fox scaling a fence at the zoo, in 2010:

Several explanations for their disappearance have been proposed, mainly habitat loss, disease and competition from coyotes. Urbanization and agricultural land conversion likely have reduced the amount of preferred habitat (forest) available for gray foxes in Illinois. But gray foxes are also highly vulnerable to canine distemper virus (CDV), which can be carried by raccoons. Coyotes are known to compete with gray foxes both directly through killing them, and indirectly by chasing them from desirable habitat. Although coyotes are able to successfully exploit highly urban areas in Chicago, they still prefer to remain in natural spaces within the city to avoid human activity as much as possible. As such, foxes (red and gray) are more commonly seen in residential neighborhoods, closer to humans, probably to avoid coyotes. It’s likely that the decline in gray foxes observed in Illinois is not driven by one single explanation, but rather a combination of these pressures.

Regardless, the sighting of this gray fox in Wilmette gives us hope that this species is still persisting in the area. It’s why long-term monitoring studies like ours are so important, enabling us to detect changes in wildlife populations over time as the environment changes around them. We have renewed hope that we will see a gray fox on our cameras, and hopefully it will be a Chicago Wildlife Watch user who sees it first!

Join in the fun! Help us identify wildlife in photos from our long-term Biodiversity Monitoring study on chicagowildlifewatch.org!

Liza Lehrer, Assistant Director
Urban Wildlife Institute, Lincoln Park Zoo

Resources: Animal Diversity Web, Willingham 2008