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Because it was part of old Gondwana and because it is insular and was isolated for tens of millions of years, New Zealand has a quirky evolutionary history. There seems to have been no mammalian stock from which to evolve on the Gondwanan fragment, and so, until the arrival of humans, there were no terrestrial mammals, nor were there any of the curious marsupials of nearby Australia—no wombats or koalas or kangaroos, no rodents or ruminants, no wild cats or dogs. The only mammals that could reach New Zealand were those that could swim (like seals) or fly (like bats), and even then there are questions about how the bats got there. Two of New Zealand’s three bat species are apparently descended from a South American bat, which, it is imagined, must have been blown across the Pacific in a giant prehistoric storm. Among New Zealand’s indigenous plants and animals are a number of curious relics, including a truly enormous conifer and a lizard-like creature that is the world’s only surviving representative of an order so ancient it predates many dinosaurs. But the really odd thing about New Zealand is what happened to the birds. In the absence of predators and competitors, birds evolved to fill all the major ecological niches, becoming the “ecological equivalent of giraffes, kangaroos, sheep, striped possums, long-beaked echidnas and tigers.” Many of these birds were flightless, and some were huge. The largest species of moa—a now extinct flightless giant related to the ostrich, the emu, and the rhea—stood nearly twelve feet tall and weighed more than five hundred pounds. The moa was an herbivore, but there were also predators among these prehistoric birds, including a giant eagle with claws like a panther’s. There were grass-eating parrots and flightless ducks and birds that grazed like sheep in alpine meadows, as well as a little wren-like bird that scampered about the underbrush like a mouse. None of these creatures were seen by the first Europeans to reach New Zealand, for two very simple reasons. The first is that many of them were already extinct. Although known to have survived long enough to coexist with humans, all twelve species of moa, the Haast’s eagle, two species of adzebills, and many others had vanished by the mid-seventeenth century, when Europeans arrived. The second is that, even if there had still been moas lumbering about the woods, the European discoverers of New Zealand would have missed them because they never actually set foot on shore.
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