Tree-Dwelling Gray Foxes Decorate With Skeletons

As the only canids that can climb trees, gray foxes frequently drag fawn and rabbit skeletons onto the branches with them.

Gray foxes in a tree

Alexander Badyaev /

A professor of evolutionary biology at the University of Arizona, Alexander Badyaev also happens to be an award-winning nature photographer. Inspired by both passions, perhaps, his curiosity was piqued by the fawn and rabbit skeletons he would often find perched on the branches of ironwood trees outside his home in the desert near Tucson, Arizona.

“Once I discovered that these trees are social centers of gray fox activity, I got hooked on observing these animals and learning their biology,” he says. As explained in the California Academy of Sciences' magazine, bioGraphic, the curious species first evolved more than seven million years ago in the lush tropical forests that once enveloped the area that is now the American Southwest.

"Since that time this anatomically distinct fox has accumulated an impressive array of un-fox-like adaptations for life in the canopy," note bioGraphic, "including primate-like flexible wrists and cat-like paws with long, curved claws that allow it to grip tree branches."

Preferring deciduous forests interspersed with brushy, woodland areas, these nocturnal sprites with retractable claws are the only canids capable of climbing trees. Their dens have even been found hidden high above the ground in hollow trunks and limbs.

In Badyaev's incredible photo seen above, a pair of gray foxes (who in general are monogamous) reign over their home in an ironwood tree, teetering high above the Sonoran Desert floor—complete with the skeleton of a fawn that had been killed by a coyote. "Fox pairs use the skeletons as pungent scent posts to mark their territories. Particularly after rain, the smell of these 'skeleton trees' can be quite powerful and can carry great distances," writes bioGraphic.

A typical territory of a breeding pair has two or three such skeleton trees, says Badyaev, noting that the skeletons are also used for resting upon. For Badyaev, a good photograph "captures the essence of a particular species—in a sense, it is the summary of all the knowledge about what the animal does and is.” For an utterly unique tree-climbing fox that festoons its home with skeletons, this photo is perfect ... make no bones about it.