Turkey Vultures and Perpetual Flight

March 2, 2015 by  
Filed under Features

In their quest for perpetual flight, researchers at Lehigh University have taken note of the turkey vulture’s amazing ability to stay aloft indefinitely with very little effort, as it scans the terrain beneath it for carrion to feed on. In addition to gauging thermals and wind direction with their own sensors, it appears that turkey vultures closely monitor other birds of prey in the area and use the information gleaned from them to determine which areas would best support their effortless soaring. It is thought that they may even keep an eye on the movement of clouds and the swaying of trees to gather information about wind currents and thermals.

Also of interest to aviation researchers, is the turkey vulture’s unique ability to hold its wings in a shallow V-shaped angle for extended periods of time which allows it to stay aloft with little effort, as well as giving it the ability to use sidewinds to its advantage, converting them into speed and altitude at a moment’s notice.

The concept of ‘dynamic soaring’ was first described in the British journal Nature in 1883 by Lord Rayleigh in an article entitled The Soaring of Birds. There he states that a bird cannot maintain its level indefinitely, either in still air or in a uniform horizontal wind, without working his wings. He concluded that if a bird maintained his course for some time, without working his wings, the conclusion can be drawn that either: The course is not horizontal; the wind is not horizontal; or the wind is not uniform – the latter being the principle relating to dynamic soaring.

Turkey vultures, also known as turkey buzzards, or simply buzzards, have a wide range of habitat, being found from southern Canada right down to the southernmost point of South America. These large scavengers favor open and semi-open terrain where they can spot their next meal with ease, feeding almost exclusively on carrion. They roost in large groups, nesting in caves, thickets, or hollow trees. As they do not have a syrinx, they can only make grunting and hissing noises. Legally protected in the United States, and with very few natural predators, turkey vultures have an IUCN conservation status of ‘least concern’.