Obligate scavenging is very rare in the animal kingdom, due to lack of enough carrion and energy. Vultures are the only vertebrates that are obligate scavengers, as being a terrestrial flyers they can find carrion more easily. Vultures as ascavenger had evolved physiological mechanism that allows them to depress their high metabolic rate by resting at their roost. Mostly vultures are found in groups or flocks around the carcasses but Red-headed Vulture (Sarcogyps calvus) is seen solitary or in pair around carcasses. Red-headed Vultures nests are also found solitary. Though it is a resident species of sub-continent but is highly terrestrial. Red-headed Vultures are also facing a serious threat from habitat loss and biotic pressure and this resulted in their consideration as a critically endangered species.
