Lakhimpur Kheri, March 16 : An Asian king vulture (Sarcogyps calvus), a critically-endangered species, has been sighted in the Sonaripur range of the Dudhwa National Park. B. Prabhakar, Dudhwa field director, said: "The sighting assumes significance as the bird has been found here almost after a decade. It encourages our wildlife conservation and habitat management efforts." Biologist Vipin Kumar during his visit in the south Sonaripur range came across the red-headed vulture sitting on a tree-top at the base camp. Surprised over this chance discovery, he recorded the sighting on his camera and informed park authorities. The red-headed vulture or Asian king vulture is listed as a critically endangered species in the International Union for Conservation of Nature (IUCN) red list. A Jatayu breeding centre was also set up in Maharajganj to protect and conserve the species. The bird weighs in the range of 3.5 to 6.3 kg. Its wings are about 1.99-to-2.6-metre long. Vultures are natural scavengers, feeding on animal carcasses and thereby, saving the environment from pollution. Notably, the sighting of several griffon vultures was reported from Katarniaghat wildlife sanctuary and in some other areas. This is a healthy sign for the Dudhwa Tiger Reserve's ecology, said Prabhakar. /IANS