Early Hunters Are Guilty as Charged. (Paleontology)
The spread of humanity around the world often coincided with extinctions of large animals. For example, when humans migrated to the Americas--traditionally dated to 11,000 years ago--around 135 mammalian species disappeared within a few hundred years. Similar extinctions occurred in Australia and on Pacific islands (SN: 12/4/99, p. 360). In New Zealand, roughly 40 bird species vanished within 5 centuries after the Maori arrived in the early 130Os.
Some scientists deny that people are to blame for these sorts of extinctions, pointing instead to such factors as climate change, says Trevor H. Worthy of Paleofaunal Surveys in Masterton, New Zealand. Even for those species clearly decimated by humans, he says, it's hard to determine whether hunting, habitat destruction, or the introduction of pests such as rats contributed most to the demise.
To address this uncertainty, Worthy and his colleagues examined bird remains at Marfells Beach in New Zealand. The area contains skeletons that accumulated without human intervention over the past 1,800 years and the bones of birds that were hunted by the early Maori. …