The world’s 100 most endangered and unique birds have been ranked in a newly published study, and the list includes a corpse-eater with legendary skills of decapitation, a shameless self-inflator, and the world’s heftiest parrot. Conducted by a team from Yale University, Simon Fraser University, and the Zoological Society of London, the study analyses where the 9,993 recognised species of birds in the world live; how many relatives they have (very few means better evolutionary distinctness); and how at risk they are in their environment.

A Californian condor flies in near the top of the list At number three is the Californian condor, a bird with a three-metre wide wingspan that has been the subject of intensive conservation efforts. Exactly how many Californian condors once lived remains unknown, yet by 1981 the wild population numbered just 21 birds. Despite numerous breeding efforts since that time, a chick did not hatch again in the wild until 2003.

At number four is the New Zealand kakapo, a flightless, nocturnal bird that is the heaviest of all parrots. It is now extinct throughout its natural range, and survives only on three small, intensively managed islands. Dedicated conservation efforts have seen the population increase slowly to 125 individuals. New Zealand kakapo 4