New research shows that the largest eagle that has ever lived on earth hunted like its modern-day relatives but ate its prey like a vulture. This extinct giant, known as the “Eagles,” grabbed and pierced live prey with its sharp claws and beak, but ate it like a vulture, digging through the carcass and dipping its head deep into the prey’s body cavity to swallow internal organs.
Scientists have long debated whether eagles (Hieraaetus mooreiThe hunter was like a vulture like today’s eagles or carnivores. The bird’s legs and claws resembled those of an eagle, but its vulture-like skull features suggest that it may have adapted to feeding on animals that had already died.
Researchers have recently solved this question by using simulations and digital models to compare this extinct giant with living birds. Analysis of the bird’s skull and claws showed which feeding behaviors of this extinct hunter were similar to those of an eagle and which were similar to those of vultures.
Host eagles lived in New Zealand and weighed up to 15 kilograms and had claws that were 9 centimeters long and their wingspan was up to three meters. These giant eagles fed mainly on moai. Moons are large, wingless birds that are now extinct and were abundant in New Zealand until about 800 years ago.
Another group of researchers reported in 2014 that around the same time, Maori people arrived on the island and began hunting moa and destroying the habitats of these forest birds. The Maori people called the eagles te hōkioi or pouākai, which means “old belly worshiper”. But it was the human appetite for the Moes that destroyed the eagles. As the Moes declined in New Zealand, so did the eagles.
In the Maori cave painting of eagles, it seems that the eagle’s head is not full.
The preserved bones of Moa, scratched by the eagle’s beak and claws, indicate that the eagles ate the Moa. But did the eagles hunt for live hair that could weigh up to 200 pounds[200 kg]?
Past studies that have analyzed the overall body shape and structure of eagle claws have shown similarities to eagle’s bones and claws, suggesting that eagles were predators. However, according to Van Heatern, lead author of the new study and head of the mammology department at the Bavarian Zoological Society in Munich, there were still questions about the features of the vulture-like skull that could not be explained by the predatory lifestyle.
For the new study, scientists created three-dimensional digital models of eagles’ skulls, beaks and claws, and compared them to the bones and claws of three species of eagles and two species of vultures. They modeled the muscles and analyzed dozens of markers on the bones to determine which parts of the legs and skull worked the hardest when hunting and feeding the extinct hunter.
Digital models identified strain points in the skulls of eagles, which the researchers then compared to similar points in the skulls of modern eagles and vultures.
“When you apply certain forces to the skull, the skull deforms slightly, so you can see how it bends during hunting or feeding,” Van Heatern told LiveScience.
The researchers measured strain levels at several points on the skull and then compared those measurements with points at the same locations in other birds’ skulls. According to the results, during some behaviors, such as catching prey in the fork, the amount of strain for host eagles was similar to other eagles. The beaks of the eagles were very similar to those of an eagle, with the potential to kill prey, but the neurocranium, where all the muscles of the neck attach, was more like a vulture.
This shows that while the eagles killed their huge prey, the moa, they ate it in the same way that carnivorous vultures ate the carcass, that is, by inserting its head into the carcass and then digging up and swallowing limbs and muscle pieces. Van Heatren says the Moes not only died of old age and were then eaten, but were also heavily hunted. But it was the prey of these giant owls that were much larger than the eagle itself, forcing the bird to feed on the oyster’s carcass like a vulture that feeds on elephant carcasses.
Eagles may have something in common with vultures: bald heads.
In art shows, this extinct bird is often depicted with a feathered head and neck. However, in the painting of the Maori people cave, which is thought to be an eagle, the body of the bird is colored, while its head is colorless, which, according to Van Heatren, we interpret as bald versus full, and this evidence also shows that eagles eat like vultures. He plunges his head into the sticky organs of his prey.
The findings were published in the Proceedings of the Royal Society B: Biological Sciences.