Black vultures (Corogyps atratus) lack voice boxes, limiting their vocalizations to hisses and grunts. This black vulture in Buenos Aires National Wildlife Refuge southwest of Tucson AZ hissed with such vigor I was uncertain whether I wanted to approach. However, the photograph won.
Black vultures are all black except for white patches on the undersides of the wing tips. Their glossy black feathers appear iridescent in the right light. The wrinkled skin on its naked head is a dark grey. The dark bill is often tipped with ivory or yellow. Black vulture legs are whitish.
Usually found in warmer climates, black vultures urinate down their legs. The evaporative process assists in cooling their bodies.
Abundant in the Southeast, black vultures are expanding up the East Coast and are local in Southern Arizona. They inhabit forested or open areas and are generally resident.
Like its red-headed cousin, the turkey vulture (Cathartes aura), black vultures are primarily carrion eaters. Unlike the turkey vulture, a black vulture will occasionally take small, live prey. Compared to the turkey vulture, a black vulture has a poor sense of smell. Where the ranges of the two species overlap, black vultures will often follow turkey vultures to carrion and then bully away the turkey vultures who located the carrion through their sense of smell.
Black vultures lay their eggs directly on the ground in sheltered areas.
I am glad its hissing did not keep me from following this magnificent New World vulture.