A rare crested coua chick, which is being hand-reared at the Wildlife Conservation Society's Central Park Zoo, displays the markings on the inside of its mouth as it prepares to receive food from its caretaker. These markings are unique for each individual chick and fade as the bird matures. The markings on the inside of a coua chick's beak are believed to be used by the parents for identification or as a target to aid in feeding. Crested couas are a species of cuckoo native to Madagascar.