Human colonisation of the remote Pacific islands may have spawned the global extinction of nearly 1,000 species of non-perching landbirds, according to a new analysis of fossil data by a University of Canberra researcher and colleagues.
Their findings were published by Proceedings of the National Academy of Sciences (PNAS), the official journal of the United States National Academy of Sciences.
Conservation ecologist Richard Duncan from the University’s Institute for Applied Ecology and colleagues have explored the magnitude and pattern of one of the largest known human-caused extinction events, which occurred on remote Pacific islands between 3,500 to 700 years ago, when overhunting and deforestation by humans wiped out thousands of bird populations.
“Up until now, details about those catastrophic extinctions had remained elusive because the fossil record documenting extinct birds was patchy and incomplete on most islands,” Professor Duncan said. “What we have done is to fill the gaps by estimating how many extinct species remain to be discovered on these islands and hence what is the true magnitude and pattern of the extinction event.”
Using a modelling approach that incorporates all the available information and addresses uncertainties in the fossil record, the researchers have quantified the loss of non-perching, or non-passerine, landbirds on 41 remote Pacific islands – which form part of the last habitable region of the Earth to be colonised by humans.
The findings reveal that nearly two-thirds of the landbird populations originally present on those islands vanished in the years between the arrival of the first humans and European colonisation.
Certain islands and bird species were particularly vulnerable to hunting and habitat destruction; these species suffered the most dramatic rates of extinction, Professor Duncan and colleagues have reported.
“Large-bodied, flightless species, such as the moa in New Zealand and flightless rails on many Pacific islands, were particularly prone to extinction most likely because these birds were large and easy to hunt,” Professor Duncan said.
“The results illustrate the rapid and widespread impacts of first human colonisation on the survival of native species.”
