Humans to Blame for Pacific Bird Extinction, Representing 10 Percent of World's Bird Species
The first humans to settle in the Pacific islands did not leave a great legacy behind; in fact, they're to blame for about 10 percent extinction of bird species in the world, according to a new study.
The finding published today in Proceedings of the National Academy of Sciences, say that 1,300 bird species went extinct in the Pacific islands between 3,500 to 700 years ago, which translates to 10 percent of all the bird populations on the planet. Estimates had previously ranged from about 800 to up to 2000 bird species and up to 8000 extinctions of local island populations.
Lead author Professor Richard Duncan of the Institute for Applied Ecology at the University of Canberra said they have been able to create the first accurate snapshot of how human settlement impacted on bird life in the Pacific Islands.
Duncan says the main problem in understanding the loss of bird life has been the incomplete fossil record from the islands.
"Consequently, many extinct bird species remain to be discovered, confounding attempts to quantify more precisely the number and type of species lost across the region," write Duncan and colleagues Dr Alison Boyer from the University of Tennessee and Tim Blackburn, of London's Institute of Zoology.
The study looked at the fossil records of 41 remote islands in the eastern Pacific that were among the last to be colonised by humans.
A total of 618 populations of 193 nonpasserine landbirds were identified on the 41 islands, comprising 371 populations present at the time of European contact and 247 populations known only as fossils.
As mankind began to occupy these islands, bird populations became extinct and habitat became limited or was removed totally as the result of deforestation in favor of human occupation.
Professor Duncan said overhunting and deforestation were behind the wipe-out. A lot [of deforestation] came through clearing through fire, and then there would be some for crops,'' he said.
"[But] we're predominantly talking about hunting for food," he added.