Ever wonder why flightless birds evolved? I doubt this applies to ostriches, given they exist on Africa, but Hawaii once hosted some flightless birds, and ARCHAEOLOGY’s Andrew Lawler covers the work of David Burney and Lida Pigott Burney on paleoecology:
The Burneys’ work suggests that, in contrast to the weedy fields where sugarcane was long cultivated, the area around the sinkhole was wooded, dominated by a species of small palm. The trade winds blew birds to the island chain, and though these ancient Hawaiian birds had no predators, being blown back to sea meant certain death. Wings, therefore, constituted a risk for larger birds, and thus flightless species arose. More than 50 species of finches hopped through the forests, each adapted to a tiny ecological niche. Two sorts of small birds called rails crept along the ground looking for the eggs of other species to snag. The only mammals on the island before humans arrived were small bats. Avians filled the ecological niches that elsewhere were occupied by grazing animals such as wild sheep and cattle, which could not survive the long journey across the ocean. “The mallard duck gets here and suddenly grows 10 times as large, stops flying, develops a beak like a tortoise, and goes out and eats the vegetation,” Burney says, gesturing up through the hole. “It’s a laboratory of evolution.”
The island’s most fearsome predator was a type of long-legged owl that caught what flying birds there were in mid-air during the day—there were no nocturnal rodents to eat—and pierced their skulls with pincer claws. “You can tell by the holes in the skulls of the victims,” says Burney.
