Palaeontologists working in New Zealand have discovered the first evidence of giant parrots, which they believe lived 19 million years ago.
An analysis of two “drumstick” bones, or tibiotarsi, found at a site on the South Island indicate the bird, named Heracles inexpectatus, grew to around one metre tall and weighed seven kilograms.
“It’s a new example of the propensity of islands to generate weird and wacky animals,” says Trevor Worthy of Flinders University, Australia.
The bird is likely to have been flightless, like several other giant flightless birds known to have evolved on islands. These include the extinct dodo, a giant pigeon that lived on Mauritius.
New Zealand was also once home to nine species of moa, a now-extinct group of large birds resembling ostriches and emus, and it is thought that H. inexpectatus would have lived alongside these. While moa typically eat leaves, the giant parrot likely ate fruits and nuts.
The structure of the bird’s bones suggests it was closely related to the kakapo, a large, flightless parrot that still lives in New Zealand today.
New Zealand has been a hotspot for bird evolution – including many flightless species – due to a lack of predatory mammals. But Worthy says that a three-metre-long, land-dwelling ancestor of the crocodile would probably have hunted the giant parrot.
A giant eagle, around the same size as the adult parrot, may have preyed on younger birds.
Journal reference: Biology Letters, DOI: 10.1098/rsbl.2019.0467
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