Soaring high in the sky with wings raised in a “V” (dihedral) shape, dark-brown to black body contrasted with gray flight feathers and tail, long “fingers” at tips, riding thermals in the sky in an unsteady, wobbly rocking motion. Turkey vultures can often be seen over fields and forests or scavenging along roadsides. No worries though they almost never attack living prey. They feed on carrion – mostly dead mammals, but also reptiles, birds, amphibians and fish.
Turkey vultures are smaller than an eagle, but larger than a red-tailed hawk with a wingspan of 67-70 inches and length of 25-32″. Their head is red and bald, unlike the black vulture that is similar in appearance and often seen roosting together, but has a bald gray head. Black vultures length is 24-27″ with a wingspan of 54-59″ and a more uniformly black body with white stars under wing tips. They roost together on poles, cell towers, dead trees and fence posts and may gather in groups of 70 at night. The black vulture soars more like a bat with fast flaps followed by short glides. Both lack vocal boxes to make proper calls so you might hear raspy hisses and grunts.
The turkey vulture and black vulture evolved independently of each other. The oldest fossil from this group is from 34 million years ago. The turkey vulture, Cathartes aura, and black vulture, Coragyps atratus, both raptors that feed on carrion, but how they locate the carrion has been long debated. Although it was believed that the black vulture primarily used visual clues to locate their next meal and the turkey vulture used their sense of smell this was not proven until 2017. Smithsonian Institution researcher and vulture expert, Gary Graves, published a report in December of that year that proved not only do turkey vultures have an extremely large olfactory bulb, an area of the brain responsible for processing odors, but they have twice as many mitral cells as black vulture despite having a brain that is 20% smaller. The olfactory bulb was four times larger and the turkey vulture has more mitral cells than any other species studied. Mitral cells are found in all animals and they help transmit information about smell to the brain. Kiwi and seabirds also have a highly sensitive sense of smell, but the turkey vulture surpasses those species.
Humans tend to be unaware of the valuable work these scavengers are doing. According to Graves they “continuously clean up all sorts of things that could cause human and livestock illnesses”. Their value became evident in India after an arthritis drug used in cattle caused a collapse in the vulture population. This led to a build-up of carcasses, contamination of drinking water, an increase in scavenging feral dogs and the resultant spike in rabies transmission to humans. As Barry Commoner wrote in his 1971 book, The Closing Circle, The First Law of Ecology: Everything Is Connected to Everything Else!
Or as Diane Lang wrote in Vulture Verses – Love Poems for the Unloved –
Turkey vulture, please be mine,
Not because you soar so fine,
But ’cause you rock on clean-up crew;
No rot is left when you are through.
Just by eating what has died,
You kill the germs that grow inside.
You deserve it, it can be said,
A pat upon your bare, red head.
Resources
Turkey Vultures Have a Keen Sense of Smell and Now We Know Why
All About Birds: Turkey Vultures