Zookeepers used a vulture puppet to avoid human imprinting while raising a chick in New York.

The king vulture chick, which hatched on February 25 at the Bronx Zoo, is being hand-raised with a stuffed figure designed to resemble an adult bird, helping ensure proper development and socialisation.

The chick's genetics are considered valuable, as its 55-year-old father has only one other living descendant. This also marks the first successful hatching of a king vulture at the Bronx Zoo since the 1990s.

Authorities said that the hand-raising technique, first developed at the zoo more than 40 years ago, involves a keeper using a puppet during feedings inside a brooder, which acts as a nest. The keeper also wears a costume to conceal human features and avoid imprinting.

The Bronx Zoo first applied this method in 1980 to raise Andean condors, which were later released into the wild in Peru. This approach has since been used for other species, including the critically endangered California condor.

Chuck Cerbini, Bronx Zoo Curator of Ornithology, said: 'This technique used in hand-raising the vulture chick incorporates the expertise from many at the zoo, including the animal care staff, veterinarians, and artists. It is a good example of the extent we go to ensure the health of individual animals and of species' populations.

'At this stage of development, our animal care staff are feeding the chick with the Bronx Zoo-made puppet once a day and we are working to ensure it does not imprint on humans. In an adjacent, separate enclosure to the chick is an adult king vulture which allows the chick to have exposure to appropriate king vulture behaviour. That's another important step we take to ensure the chick grows into a healthy adult bird and is properly socialised as a king vulture.'

King vulture chicks are born with white down feathers. They begin growing juvenile feathers at around four months old, with full adult plumage appearing by age four.

While the king vulture is classified as 'Least Concern' by the IUCN, it faces threats from habitat loss and poaching across its range, which stretches from southern Mexico to northern Argentina and Uruguay.