 At the zoo's National Center for Artificial Incubation of Raptor Eggs, eggs of raptors that are either extinct or severely decimated in Israel are incubated from captive-breeding pairs.The griffon vulture, an endangered species, is the subject of much research activity.The zoo has successfully mated vultures with crippled wings – a feat that ornithologists previously thought could not be accomplished because these birds could not balance themselves properly.