The red fox is reddish from head to tail to toe. If you see a fox of dappled russets and grays, however, you have found the classic small predator of oak woods and savannas, Urocyon cinereoargenteus, the gray fox.

The gray fox is a tree climber. Notice those short legs. They, along with long, curved claws, mark the only canid (the dogs, wolves, coyotes, and foxes) that is adapted to life in the trees. The gray fox has been called a "primitive canid;" its lineage has been separate from all the others for more than four million years. As the legs of the others have become more and more specialized for running, the gray fox has developed limbs more like those of bears, cats, and humans. They're good at hugging.

Step back a few hundred years, and the large mammal predators of Chicago Wilderness consisted of cats, bears, otters, badgers, and three canids. Wolves ruled. Coyotes survived by wiliness. Gray foxes climbed trees.

That adaptation continues to benefit the grays today. Gray foxes are said to do better than reds where there are coyotes, because of their knack at tree climbing.

But gray foxes don't like tall trees that grow close together all that much. True, people report seeing them napping in crow or hawk nests as high as 60 feet off the ground. But gray foxes eat mostly rabbits and mice — with occasional hors d'oeuvres of fruit, birds, eggs, and insects. Their food thrives in the open oak-hickory woodlands and grassy oak savannas. They're most at home in crooked trees with big, spreading limbs. That straight ash tree on the right suggests a woods of gradually deepening shade, and diminishing life in the understory. The gray fox won't long thrive in this woods, unless a fire or some land managers come through to thin the ash trees and encourage the oaks, shrubs, and wildflowers.

Look for Urocyon cinereoargenteus in woods full of light and butterflies and the most colorful birds. It's an animal of the classic Chicago Wilderness.

Photo by Joe Nowak. Words by Stephen Packard.