That's a big eagle
Remember the Moa? Giant flightless bird about 13ft to the top of its head? Yeah, pretty big bird, and living on New Zealand, too, where there's not much in the way of native predators. Lots of crazy birds have evolved there, making use of the fact that New Zealand doesn't (natively) have canines or felines or mustelids or any other common mammalian predators that you can find just about everywhere else (excluding lots of remote islands, of course). The Moa is probably one of the most impressive of New Zealand's native fauna, and it wasn't until humans came to New Zealand that they started to have a hard time and eventually died out.
But the Moa had a natural predator. And it was a really big one.
Ladies and gentlemen, I present to you Harpagornis moorei, the Haast's Eagle.
The Haast's Eagle is, quite simply, the largest eagle to ever have lived. Its wingspan of 8 to 10 feet was not much larger than extant eagles today, such as the Golden Eagle (big female Goldens can have an 8 foot wingspan), but that's because it had evolved to fly in dense forests, where a big wingspan is problematic, as compared to soaring over open plains and mountains that Goldens prefer, where a big wingspan is necessary to maintain soaring flight. The Haast's Eagle, however, weighed up to 33 pounds; that's more than twice the weight of a big female Golden Eagle. That's also getting very close to the weight limit for a bird to still be able to attain powered flight; the heaviest extant birds capable of flight are a few species of bustards, which weigh roughly the same.
The Haast's Eagle was so big because it could be. With no competitive predators on the ground capable of challenging it for its meals, it was able to get big enough to tackle Moa. This eagle could kill a bird that stood 13 feet tall and weighed 600 pounds. Granted, it probably focused on younger and smaller birds as easier targets, but it was completely capable of killing an adult Moa.
Why don't we see big eagles like that elsewhere, like in Africa where there's ostriches? Because if there was an eagle big enough to take down an ostrich, you can bet that eagle would quickly have its kill stolen by jackals, hyenas, lions, whatever else is out there. And 33 pounds may be a really heavy flighted bird, but birds still have hollow bones that don't stand up to much punishment if something decides to fight it for its food. Most extant birds of prey focus on hunting prey that they can conceivably carry away, weighing less than their own body weight, so that they don't go through the effort of killing it and then end up losing it to some land-based bully. Martial Eagles have been known to kill impala, Golden Eagles have been known to go after deer fawns, but mostly, these birds are limited in prey selection based on what they can carry away after killing. With no land-based predators in New Zealand save tuataras (which don't get very big), the Haast's Eagle could kill a Moa and dine at its leisure, getting its fill, and returning over the next howeverlong it took to finish it off, without having its food stolen. Its only competition for its prey was other eagles. A flightless species of duck (now also extinct) was probably the Haast's Eagle's food of choice, but so many fossil remains of Moa with damage that could only have been inflicted by this eagle's talons have been found that it is an accepted fact that Haast's Eagle hunted and killed Moa.
The Haast's Eagle was thought to be related to the Wedge-tailed Eagle of Australia, but recent evidence shows that its nearest living relative may be the Little Eagle, an eagle roughly the size of a Peregrine Falcon, weighing no more than 2 pounds. That's some serious evolution, there.
By the way...remember how the Moa died out after humans (specificly, the Maori) came to New Zealand? That happened to a lot of other species in New Zealand, especially since so many birds had evolved to flightlessness. Haast's Eagle didn't last too long after its prey started dying out, and its forests started getting burned and cleared. But think about it. Your hunting territory has been invaded by skinny hairless apes that, at their biggest, stand less than half the height of a grown Moa and weigh about a third as much. They're also not covered in coarse feathers that are a pain to pluck off your prey. Hmmmmmm...
There's no evidence to support it, but c'mon. Even putting into account that humans tend to carry around weaponry and kill things with said weaponry, a Maori child would make a very tempting target for a predator whose favorite prey is getting harder and harder to find, a predator that's capable of bringing down stuff much larger than that. The Haast's Eagle could have hunted and killed humans.
That's a seriously badass bird. Too bad it only lasted a few centuries after the Maori came to New Zealand.
(Mods: Suggested tag is "haast's eagle".)
But the Moa had a natural predator. And it was a really big one.
Ladies and gentlemen, I present to you Harpagornis moorei, the Haast's Eagle.
The Haast's Eagle is, quite simply, the largest eagle to ever have lived. Its wingspan of 8 to 10 feet was not much larger than extant eagles today, such as the Golden Eagle (big female Goldens can have an 8 foot wingspan), but that's because it had evolved to fly in dense forests, where a big wingspan is problematic, as compared to soaring over open plains and mountains that Goldens prefer, where a big wingspan is necessary to maintain soaring flight. The Haast's Eagle, however, weighed up to 33 pounds; that's more than twice the weight of a big female Golden Eagle. That's also getting very close to the weight limit for a bird to still be able to attain powered flight; the heaviest extant birds capable of flight are a few species of bustards, which weigh roughly the same.
The Haast's Eagle was so big because it could be. With no competitive predators on the ground capable of challenging it for its meals, it was able to get big enough to tackle Moa. This eagle could kill a bird that stood 13 feet tall and weighed 600 pounds. Granted, it probably focused on younger and smaller birds as easier targets, but it was completely capable of killing an adult Moa.
Why don't we see big eagles like that elsewhere, like in Africa where there's ostriches? Because if there was an eagle big enough to take down an ostrich, you can bet that eagle would quickly have its kill stolen by jackals, hyenas, lions, whatever else is out there. And 33 pounds may be a really heavy flighted bird, but birds still have hollow bones that don't stand up to much punishment if something decides to fight it for its food. Most extant birds of prey focus on hunting prey that they can conceivably carry away, weighing less than their own body weight, so that they don't go through the effort of killing it and then end up losing it to some land-based bully. Martial Eagles have been known to kill impala, Golden Eagles have been known to go after deer fawns, but mostly, these birds are limited in prey selection based on what they can carry away after killing. With no land-based predators in New Zealand save tuataras (which don't get very big), the Haast's Eagle could kill a Moa and dine at its leisure, getting its fill, and returning over the next howeverlong it took to finish it off, without having its food stolen. Its only competition for its prey was other eagles. A flightless species of duck (now also extinct) was probably the Haast's Eagle's food of choice, but so many fossil remains of Moa with damage that could only have been inflicted by this eagle's talons have been found that it is an accepted fact that Haast's Eagle hunted and killed Moa.
The Haast's Eagle was thought to be related to the Wedge-tailed Eagle of Australia, but recent evidence shows that its nearest living relative may be the Little Eagle, an eagle roughly the size of a Peregrine Falcon, weighing no more than 2 pounds. That's some serious evolution, there.
By the way...remember how the Moa died out after humans (specificly, the Maori) came to New Zealand? That happened to a lot of other species in New Zealand, especially since so many birds had evolved to flightlessness. Haast's Eagle didn't last too long after its prey started dying out, and its forests started getting burned and cleared. But think about it. Your hunting territory has been invaded by skinny hairless apes that, at their biggest, stand less than half the height of a grown Moa and weigh about a third as much. They're also not covered in coarse feathers that are a pain to pluck off your prey. Hmmmmmm...
There's no evidence to support it, but c'mon. Even putting into account that humans tend to carry around weaponry and kill things with said weaponry, a Maori child would make a very tempting target for a predator whose favorite prey is getting harder and harder to find, a predator that's capable of bringing down stuff much larger than that. The Haast's Eagle could have hunted and killed humans.
That's a seriously badass bird. Too bad it only lasted a few centuries after the Maori came to New Zealand.
(Mods: Suggested tag is "haast's eagle".)