In the last ten days there have been announcements about two different giant birds that used to live in New Zealand. There’s a human-sized penguin that flourished during the Paleocene – the first age after the dinosaur extinction event – and a one-metre tall parrot that lived some tens of millions of years later in the early Miocene. That era is still ancient to us: it lasted from 23 to 5 million years ago, so the one thing that we can say about this giant parrot is that it’s dead.
It’s not surprising that either species of bird existed. Island gigantism (or, sometimes, its flip-side, dwarfism) is a known evolutionary phenomenon associated with isolation. And New Zealand was literally the lost world of Professor G. E. Challenger – a place where the surviving dinosaurs – birds – dominated. When humans first arrived around 1300 AD (give or take a few years) there were no mammals apart from a species of bat; and the place retained its Cretaceous-era flora, filled with birds that had expanded into most of the available ecological niches. Some, such as the moa, were enormous.
Other giant New Zealand birds included the largest eagle in the world, Haast’s Eagle (Harpagornis moorei). Let me put that in perspective. The Bald Eagle that Congress adopted in June 1782 as a symbol of the United States has a typical wingspan of between 1.8 and 2.3 metres, and a body weight of typically between 4 and 5 kg, which is impressive. But not record-holding. That goes to Haast’s Eagle, where the females weighed in at up to 15 kg, though the species had remarkably short wings for its size, a span of just 2.6 – 3 metres. But they had a far longer chord – making them chunkier – and the bird itself had a massive tail for its size. Flight speed was up to 80 km/h, and it has been estimated that these eagles could strike prey from the air at that speed – implying a kinetic energy of 3703.7 joules and a momentum of 333.33 kg-m/s. Just to put that in perspective, this is roughly the same net total energy as that of a 1.8 kg bird striking the windscreen of an airliner at 670 km/h. Being attacked by one, in short, was not unlike being slammed over the head with concrete block dropped from a height. And they did, apparently, attack humans.
I have to say ‘was’ because the eagle, moa and many other species vanished before the onslaught of human appetite and environmental destruction. Like the giant parrot, they are dead. Others survived, however, including several species of parrot – notably the Kea (Nestor notabilis). These birds weigh up to 1 kg, or a little more, and are around 48-48 cm long. The Kākāpō (Strigops habroptilus) is flightless and much larger with a length of up to 64 cm and a typical weight of between 2 and 4 kg. They aren’t dead, but the species is severely endangered. Even after a sustained effort to save them, just 142 specimens are known to be alive. If you want to contribute to the recovery, go here: https://www.doc.govt.nz/our-work/kakapo-recovery/
And now it turns out that they had a giant cousin, the dead parrot from the Miocene announced last week in a letter to the Royal Society. The bones were first discovered in central Otago in 2008, and have been sitting since in Te Papa Tongarewa, the national museum. But they were not recognised for what they were until recently when a research project at Flinders University uncovered what they actually were. They came from a parrot that stood at least 1 metre tall and weighed perhaps 7 kg. The discoverers named it Heracles inexpectatus (Hercules the unexpected).
The discoverers suggest the evolution of such a giant parrot might be related to the sub-tropical fauna of Miocene New Zealand. Doubtless more remains to be discovered about these incredible birds; but I can’t close without pointing out one of those curious coincidences of name. The Miocene era in which they lived was named by Charles Lyell. His name, in turn, was given to a locale in New Zealand’s West Coast, Lyell, by the geologist Julius Haast – whose name, in turn, then went to the giant eagle. Science wasn’t such a large field in the mid-late nineteenth century.
In a way it’s a pity the giant parrot didn’t survive to the present, unlike their cousins. Although you can imagine what that kind of bird would do to tourist hire cars. Kea, which are less than half the size, already vandalise cars very effectively. So I guess it’s kind of lucky that Squawkzilla the Giant Flightless Parrot is no more. They have ceased to be – and, well, I could carry on, but you know where this is going…
Copyright © Matthew Wright 2019