February is the heart of winter in the Sky Islands. Cold temperatures, overcast and rainy days, as well as howling winds can all combine to make life challenging for local wildlife. Herbivores and omnivores have less to eat in the way of plant-based food – spring’s ephemeral wildflowers not withstanding in some years. If the elements and dearth of sustenance are extreme enough or if you hit the wrong predator lottery, then bad goes to worse and you, quite simply, are dead.
The ultimate fate of all life is death and from these proverbial ashes other life thrives – the scavengers. This often reviled, little loved, and motley group of creatures make their living (at least in part) from the demise of others. Flanks of fresh or fetid flesh fills their fare when they’re fortunate to find it. All dead animals get consumed eventually. Otherwise, we’d be tripping over ever-accumulating carcasses. We, then, collectively owe a great debt to the species that consume the demised.
Perhaps the ultimate of nature’s “zombies” is the familiar Turkey Vulture. It seems to dress the part, cloaked as it is in black feathers and with a stark, bare, and blood-red head. Black, after all, is the color of death – no? Likely the very fact that many scavenging birds sport black plumage spawned the association of this color with death. Black is no more “the color of death” than is, say, turquoise! Nevertheless, Turkey Vultures are superb at finding and devouring a wide range of carrion.
Unlike most birds, they have evolved a keen olfactory sense, which helps them hone in upon their gruesome food. Awaiting the warmth of the sun, they’ll spread their wings and sun themselves. This gradually heats up their flight muscles to more efficient temperatures. Next it’s up on local thermals of air, soaring high above the landscape on dihedral wings. There, their keen vision along with their sense of smell often leads them to a carcass. Along with the obvious larger meals, like a roadkilled deer, Turkey Vultures are also able to detect even squirrel-sized bodies rotting in forested habitats. In controlled experiments, researchers hid such would-be meals from these scavengers, but to no avail. The vultures easily found the bodies. This ability to detect smaller meals serves the species well, as over millennia they’ve had to compete for bigger carcasses with the formerly more widely spread California Condor and a host of other scavengers.
Now that the condor, a Pleistocene holdover, is critically endangered you might think that Turkey Vultures would be liberated from competition. Such is not the case locally. In southeast Arizona we host a stable population of Black Vultures – the only ones west of Texas. Despite what appears to be a smaller overall size, Black Vultures weigh about the same as their cousins. They typically fly higher than Turkey Vultures, watch them, and follow them down to the prize. At the body itself they often feed so frenetically that they wind up chasing their kin away!
Carcasses are generated through disease, predation, and vehicular collisions. They provide food not only for vultures, but also other local species. Watch for both our species of ravens – Chihuahuan and Common – plying local thoroughfares for an easy meal. The larger Common Ravens easily dominate their smaller kin at the feast. Even Golden and Bald Eagles will get in on the act, subordinating all the avian competitors at a carcass. Golden Eagles have even killed California Condors! The Crested Caracara – a sort of strange falcon – is a notable scavenger. Look for it in the Altar Valley. Able to subdue its own prey, it won’t pass up an easier meal. It will dominate all but the eagles when scavenging.
Nor are birds our only scavengers. Mammals too get in on the surfeit. Several years ago I watch in astonishment as a bobcat ate a road-killed collared peccary (javelina) on Route 82. So intent was this cat upon its breakfast that it only trotted off the road for a few seconds, quickly returning to its feast as I drove by! Coyotes are more often the beneficiaries of a dead animal, efficiently making short work of the body. The list goes on – other carnivores, mice, flies, carrion beetles, bacteria, etc….
So the next time you feel sorry for the dearly departed, think about nature’s collective clean-up crew. They too need to eat and despite the fact that they may revolt you, without them the cycle of life would be broken.
Vincent Pinto and his wife, Claudia, run Raven’s Way Wild Journeys. They offer local tours dedicated to the preservation of the incredible biodiversity in the Sky Islands.