The King vulture (Sarcoramphus papa) is a large bird found in Central and South America. It is a member of the New World vulture family Cathartidae. Its more powerful features, for the purpose of feeding from the toughest animal carcasses, have given the King vulture its name; its larger size, brilliant color, and adapted features. Other birds treat the King vulture as the king, for example, when it flies in, other birds will stop feeding and let it eat.
An imposing bird, the adult King vulture has predominantly white plumage, which has a slight rose-yellow tinge to it. In stark contrast, the wing coverts, flight feathers, and tail are dark grey to black, as is the prominent thick neck ruff. The head and neck are devoid of feathers, the skin shades of red and purple on the head, vivid orange on the neck, and yellow on the throat. On the head, the skin is wrinkled and folded, and there is a highly noticeable irregular golden crest attached to the cere above its orange and black bill; this caruncle does not fully form until the bird's fourth year. The King vulture has, relative to its size, the largest skull and braincase, and strongest bill, of the New World vultures. This bill has a hooked tip and a sharp cutting edge. The bird has broad wings and a short, broad, and square tail. The irises of its eyes are white and bordered by bright red sclera. Unlike some New World vultures, the King vulture lacks eyelashes. It also has gray legs and long, thick claws. The juvenile vulture has a dark bill and eyes, and a downy, gray neck that soon begins to turn the orange of an adult. Younger vultures are a slate gray overall, and, while they look similar to the adult by the third year, they do not completely molt into adult plumage until they are around five or six years of age.
King vultures live in the south of Mexico and throughout South and Central America to northern Argentina. Mainly frequenting humid tropical forests, they may sometimes be seen in more open areas like savannah and grasslands. These birds prefer undisturbed forests inhabited by large mammals. They are also often seen near swamps or marshy places in the forests.
King vultures do not gather in large groups but remain in family units. They mostly stay out of sight, perched high up in the canopy, or they are flying about and soaring high above the ground looking for food. They do not migrate, remaining within the same area all year long. They are a diurnal species and much of their time is spent basking in the sun and saving their energy, sometimes preening their wing feathers. King vultures, unlike some other vulture species, have a poor sense of smell, relying on other vultures to locate prey, and then descending to join in the feeding. These birds are very rarely aggressive, usually backing down instead of fighting. Due to their large bodies and wings, they totally depend on air currents for their flight, and avoid flapping their wings unless they really have to. King vultures do not have a voice box (a syrinx) or the muscles needed to make it work. They can make very low croaks. During the breeding season, they will give warning sounds when something approaches their nest.
King vultures are carnivores and scavengers, eating carrion almost exclusively, including dead fish along the shores of streams.
King vultures are monogamous and their pair bonds last for life. They are often seen perching high in trees under cover or soaring very high up in the sky. As a result, their courting ritual is only seen in captivity, being a display where both birds walk around on the ground in circles while they flap their wings. They make loud snorting and wheezing noises during mating. Breeding usually takes place during the dry season. These birds are solitary and so do not gather in big colonies to nest. Instead of building nests, they lay their eggs in a stump the hollow of a rotting log, or a crevice in a tree. A single egg is laid and incubation lasts for around 55 to 58 days, with both parents regularly taking turns. Chicks are naked when they hatch but very soon acquire pure white down. The parents bring food to them in their claws, but also feed their chick by regurgitation. Young fledge at 3-4 months, but remain dependent on their parents until they are eight months old and may stay close to them for two more years. At three to four years of age, a chick has developed all its plumage and other features. Females become reproductively mature at around 5 years of age, and males at around 7 years of age.
Although King vultures are not listed universally as endangered, populations are decreasing as a result of habitat destruction. They will not be able to survive if the forests where they live disappear.
The IUCN Red List reports the total King vulture population size as 1,000-10,000 individuals, approximately equating to 670-6,700 mature birds. However, another study suggests there are fewer than 50,000 individuals in total. Overall, currently, King vultures are classified as Least Concern (LC), but their numbers today are decreasing.
King vultures have an important role in the ecosystem in which they live. They usually find dead animals first and immediately begin to eat the rotting remains. As with all scavengers, their actions are important to keep the environment free of dead and decomposing animals, which may help reduce sources of disease.