Is this what the long-extinct Haast's eagle looked like? New research has changed what we know about the prehistoric predator. Image / Katrina Kenny
Is this what the long-extinct Haast's eagle looked like? New research has changed what we know about the prehistoric predator. Image / Katrina Kenny
New Zealand's goliath, long-lost Haast's eagle, or pouākai, gulped down the guts of its prey like a vulture – and may have even been bald.
That's according to a just-published study that's shed more light on what was the world's largest eagle, and whose demise quickly followed that of its much-larger prey, the moa, which was hunted to extinction some 600 years ago.
Research has told us the giant predator's claws were as much as 9cm long - making them as large as those of a tiger – and that the bird was most likely to have been a sombre brown or brownish-grey, similar to the other very large forest eagles found around the world today.
Evidence of talon marks on moa skeletons confirm that they predated on these large birds - prey that weighed up to 200kg.
But they also would have targeted other flightless birds - particularly Aptornis, weka, takahē, flightless geese and ducks - and potentially even unfortunate humans.
Haast's Eagle compared to the size of an average man. Image: Steve Wroe
In a new study, an international team of researchers, including Canterbury Museum senior curator Dr Paul Scofield, compared the skull, beak and talons of a Haast's eagle with those of five living meat-eating birds, to learn about the extinct raptor's feeding habits.
The fresh insights yielded a much clearer picture into how the eagle fed.
"Most eagles hunt prey that is smaller than them, but Haast's eagle was going after moa that could weigh up to 200kg – more than 13 times their own body weight," Scofield said.
"Condors also often eat animals that are much larger than them, so it makes sense that they'd have similar feeding habits.
"As a result of this research, when we picture a Haast's eagle feeding we can imagine them swooping down on a moa, grabbing on with those huge talons and using its powerful beak to deliver the killing blow.
An earlier artist's impression of a Haast's eagle attacking two moa. Scientists now suspect the bird may have been bald - and fed on its prey like a condor. Image / John Megahan
"Once the moa was down, the eagle would go straight for the back of the skull and for the guts and other soft organs."
The study found that the beak and talons of the bird were similar to those of eagles that we know today.
However, the shape of its neurocranium – the section of skull that encloses the brain, and a key indicator of feeding behaviour in birds – was most like that of the Andean Condor, a South American vulture.
The condor was a "gulper" - or a bird that feeds on the soft internal organs of a carcass.
Its similarities to the Haast's eagle suggested the giant eagle probably also feasted on the guts and other internal organs of its prey.
If Haast's eagle indeed ate like a condor, its head and neck might also have been featherless like that of the condor and most other vultures.
That theory was supported by a Māori drawing thought to depict a pouākai or Haast's eagle in the Cave of the Eagle at Craigmore Station in South Canterbury.
A Māori drawing, found in the Cave of the Eagle at Craigmore Station in South Canterbury, is thought to depict a Pouākai or Haast's eagle. Image / Gerard Hindmarsh
In the drawing, the eagle's body was coloured black - but its head and neck are uncoloured.
Since Haast's eagle was formally described by Julius von Haast in 1872, scientists have debated whether it was a predator that killed other animals for food or a scavenger that ate animals that had already died.
In recent years, however, consensus has shifted towards the eagle being a predator – one that evolved to hunt the large flightless moa that roamed Aotearoa New Zealand before humans arrived.
This new research supports the predator theory.
Haast's eagle talons were similar to those of today's eagles, in particular Australia's wedge-tailed eagle, although they were much larger and more powerful.
These similarities suggest that, like other eagles, Haast's eagle used its talons to hunt.
Researchers have maintained its population began its slide into extinction when the availability of its key food, the moa, started to dwindle.
The bird happened to be the largest terrestrial carnivore around when humans arrived on our shores, more than 700 years ago.
It must have been an intimidating sight for them: the eagle's sheer size, and a body weight comparable to that of a toddler, meant it could strike with a force equivalent to a concrete block falling from the top of an eight-story building.
