E is for Eagle

The eagle has been a symbol of nations for millennia, in part because they’re strong, majestic birds of prey. Some species lay two eggs, only to have one hatchling kill the other one, which takes sibling rivalry to a whole new level.

Eagles exist in many parts of the world, but the largest eagle that ever existed lived in New Zealand—until some 400 years ago.

Haast’s Eagle had a relatively short wingspan (2.6–3 metres, or about 8½ feet to nearly 10 feet), but with massive flight muscles it weighed between 9 and 15kg (20-33 pounds). They preyed on the large flightless birds in New Zealand, chiefly the moa, which were 15 times heavier than the eagles (the picture above depicts a Haast’s Eagle attacking a moa).

The eagles evolved from smaller eagles in response to the abundance of food in New Zealand, in part because it had no competition—at least, not until humans arrived.

When Maori arrived in New Zealand, they hunted the large flightless moa and other birds to extinction, and once the birds were gone, Haast’s eagle died out, too, roughly 400 years ago. Still, they may have had a bit of revenge: Maori legends talk of the Pouakai, which killed humans, and that could well be referring to Haast’s Eagle (and that’s the Maori name most commonly used now to refer to the eagle). Certainly the eagle would have been capable of killing humans, especially children.

The largest bird that ever flew was not an eagle, however, but the extinct Argentavis magnificens, a relative of the modern Andean Condor, which is one of the largest flying land birds still alive. It is estimated to have had a wingspan of 7 metres (23 feet) and a weight of 70-78kg (150-172 pounds). The heaviest living birds are a couple species of buzzards and the bird with the largest wingspan today is the Wandering Albatross (3.65 metres, or 12 feet). Not an eagle in the bunch.

Eagle can also refer to a golf term, but I don’t play the game, so I couldn’t possibly comment. But I do remember (and always liked) these guys.

I think Haast’s Eagle is fascinating bird. But I’m kind of glad I never met one.

The image at the top of this post is a Creative Commons licensed illustration, “Giant Haast's eagle attacking New Zealand moa” (2004), by John Megahan, published by PLoS Biology and available for download through Wikipedia.