Bird Species Spotlight: King Vulture

On a recent trip to Costa Rica, I was introduced to an entirely new bird species for me, namely, the “king vulture.” This photographic workshop that I attended in Costa Rica was organized and hosted by Naturescapes.net, a specialized travel agency for photographers, and an invaluable resource for them as well. The workshop was led by Greg Downing, the founder and owner of NatureScapes, and Greg Basco. Between the one-on-one assistance of these two professionals, it seemed almost impossible to make a mistake or miss an important shot. Truly, this was the trip of a lifetime for me and I came home with over 5,000 images from this 10-day trip.

King vulture landing. © Jake Jacoby

There were 8 photographers in our group. We visited one particular lodge that had figured out, and implemented a plan, to photograph king vultures without changing their behavior or habituating them to humans—no small feat. In a large field about a ¼ mile from the lodge, lodge workers dug a series of 2-to-3 foot deep holes in the ground. Then they erected large and natural tree-limb perches behind the holes for the birds to rest on while they were feeding. The lodge had previously constructed two blinds (hides), one slightly higher than the other for a differing point of view. Each blind held 5 people, 4 photographers and one workshop leader. The lodge had purchased cattle heads from a nearby slaughterhouse (these heads would have been otherwise discarded) and placed them in the holes. Black-headed Vultures arrived first and were quickly followed by king vultures. We were then able to observe and photograph the vultures from our blinds without disturbing the birds as they fed on the cattle head carrion. Interaction between the vultures and their feeding ritual was at times, so interesting, that I just laid my camera down and watched.

Immature king vulture. © Jake Jacoby

Without a doubt, the king vulture is more colorful and appealing than any other species of vulture that I have ever seen. They are sexually dimorphic (no difference in plumage and very little in size between males and females). They spend much of their time perched high in the trees and live mainly around the savannas and the forest regions of Central and South America. Specifically, they are found from Southern Mexico South to Northern Argentina and are endemic to the Americas. They live in small groups or in solitary so they usually don’t have to worry about competitors for their food. They are primarily sedentary (non-migratory) and have a talent for being able to conserve their energy by being able to glide effortlessly aloft on their long, broad wings, using the currents from the wind for long periods of time. They have no syrinx (voice box) so they make no calls or sounds.

Like all vultures, the king consumes carrion, the remains of dead animals. They are scavengers and able to consume animals that have recently died or that had been left to rot in the heat thereby creating a health hazard; and, they are able to do this without getting sick. This is something that very few other types of living things are capable of doing, and as a result, offer a necessary element in the balance of nature; to be more precise, they are nature’s sanitation workers on land. They will feed on the carcasses of many types and sizes ranging from dead fish, lizards, sloths, and monkeys, up to cattle. They have a thick, strong beak which is well adapted for tearing, and long thick talons for holding the meat. They have keen eyesight and a good sense of smell, and they use both to find food.

Taking flight. © Jake Jacoby

All vultures have a bare head which prevents feathers from matting with blood when reaching inside a carcass. King vultures have a large pouch in the throat (crop) and can go for long periods without food. This is an adaption to a feast-or-famine scavenging lifestyle. King vultures grow to about 2.5 feet tall, have a wingspan to 5 to 7 feet and weigh upwards of 8 pounds, making them the largest New World vulture, except for condors. When feeding, vultures maintain a strict social order based on body size and strength of beak. Smaller vultures like the black vulture, wait for scraps left behind by the larger dominant species. So, when a king vulture lands, other birds make way for it because of its large size. Using its bill to tear, it makes the initial cut in a fresh carcass. This allows the smaller, weaker-beaked vultures, which cannot open the hide of a carcass, access to the carcass after the king vulture has fed. The vulture’s tongue is rasp-like which allows it to pull flesh off of the carcass’s bones.

Juvenile king vulture. © Jake Jacoby

These vultures are monogamous and mate for life. They generally lay one egg in a nest on the ground in a tree stump, a hollow log or some other natural cavity. Their nest consists of very little material; usually just scratched out of the existing material or soil. To ward off potential predators, the vultures keep their nests nasty and foul-smelling. Both parents incubate the egg for approximately 2 months until it hatches. The parents share incubating and brooding duties until the chick is about a week old, after which they often stand guard nearby rather than brood.

The young are semi-altricial (helpless when born) but are covered in downy feathers (truly altricial birds are born naked), and their eyes are open at birth. The parents bring food to the chick in their talons, but will also feed them by regurgitation. After one to three months of age, chicks will walk around and explore the vicinity of the nest. Young birds are sooty dark and attain their white plumage and colorful head and neck of adults gradually over the course of their first 4 years. They will take their first flight at about 3 months and, as stated above, develop their bright, garish head colors at 4 to 5 years; at which time they will also be ready to breed.

Man is the only known predator of the king vulture. On occasion, ranchers have been reported to have killed them by shooting and/or poison in order to protect their livestock and service animals.