A new study from Tel Aviv University’s School of Zoology indicates that humans caused the extinction of many hundreds of bird species over the last 50,000 years.
The study, carried out in cooperation with the Weizmann Institute, took a comprehensive look at scientific literature on extinct birds and listed at least 469 avian species that have disappeared from the world in the past few tens of thousands of years, based on remains found in archaeological and paleontological sites around the globe.
However, “we believe that the real number [of species] is much higher,” the scientists said.
The researchers think the extinctions were caused primarily by humans who hunted the birds for food, or by animals introduced into ecosystems by humans that then fed on the birds and/or their eggs.
They noted that many of the ancient remains were found in human sites and appeared to have been eaten, and that a species’ disappearance appeared to occurr shortly after humans arrived in the area.
The researchers believe humans may be responsible for the disappearance of some 10-20 percent of all avian species. They said that the vast majority of the extinct species shared several features: They were large, they lived on islands and many of them were flightless.
They posited that such birds were easier targets for humans as well as enticing, as each slain bird provided its hunters with large amounts of food.
They noted one well-documented example being the moa bird in New Zealand, with 11 species of moa becoming extinct within a few hundred years after the arrival of humans there.
According to Prof. Shai Meiri of Tel Aviv University, who led the research, “Our study indicates that before the major extinction event of the past millennia, many more large, even giant, as well as flightless avian lived on our globe, and the diversity of birds living on islands was much greater than today.”
He added: “We hope that our findings can serve as warning signals regarding bird species currently threatened with extinction, and it is, therefore, important to check whether they have similar features. It must be noted, however, that conditions have changed considerably, and today the main cause for the extinction of species by humans is not hunting but rather the destruction of natural habitats.”
The research was published recently in the Journal of Biogeography.