Black vultures do not build nests but rather lay one to three eggs in tree cavities or stumps, caves, abandoned buildings, or thickets. Both parents take turns incubating the eggs for the next 38 to 39 days.
Black vultures keep close social ties with their extended families throughout their lives. They are monogamous and stay with their mates year round for many years and feed their babies as long as eight months after they have fledged. Although they roost in large flocks, the vultures prevent non-family members from joining them.
The most common vulture in the Western Hemisphere, black vultures are widespread from southern South America northward through Central America and Mexico into the southeastern United States and southern Arizona. Their range has expanded further north in the last few decades. More plentiful road kill and the warmer temperatures caused by global warming results in carcasses staying unfrozen, have contributed to the birds’ northward expansion. Most common at low elevations, they usually nest and roost in dense forests but fly above open areas when searching for food.
Feeding primarily on carrion—the decaying flesh of a dead body—black vultures will sometimes kill and eat skunks, opossums, young leatherback sea turtles and night-herons, as well as newborn calves and sheep. Soaring high into the air on thermal currents, the vultures can spot carcasses themselves, but they also keep an eye out for lower-flying turkey vultures, which, with their superior sense of smell, may sniff out carrion and lead the black vultures to a meal. The black vultures, traveling in large flocks, then drive off the turkey vultures.
Black vultures of both sexes have bulky black bodies with short tails but broad wings that span about five feet and have white feathers under their tips. Their dark gray heads are featherless and wrinkled with narrow, sharply-hooked bills excellent for reaching deep into decaying bodies. The birds weigh about 56 to 77 ounces and are about 23 to 27 inches long. Black vultures fly with quick, strong wing beats followed by a short glide. Not having a voice box, the birds are limited to hisses and grunts. Their habit of urinating down their legs allows them to cool the blood in their lower extremities and then send that blood through the rest of their body.