Humans putting 1,700 animal species at greater extinction risk: Study

Increased human land-use may put 1,700 species of amphibians, birds, and mammals at greater extinction risk over the next 50 years, by shrinking their natural habitats, a study has found. The study, published in the journal Nature Climate Change, combined information on the current geographic distributions of about 19,400 species worldwide with changes to the land cover projected under four different trajectories for the world scientists have agreed on as likely.

These potential paths represent reasonable expectations about future developments in global society, demographics, and economics.

"Our findings link these plausible futures with their implications for biodiversity," said Walter Jetz, a professor at Yale University in the US.

"Our analyses allow us to track how political and economic decisions -- through their associated changes to the global land cover -- are expected to cause habitat range declines in species worldwide," Jetz said in a statement.

The study shows that under a middle-of-the-road scenario of moderate changes in human land-use about 1,700 species will likely experience marked increases in their extinction risk over the next 50 years.

They will lose roughly 30-50 per cent of their present habitat ranges by 2070, the researchers said.

These species of concern include 886 species of amphibians, 436 species of birds, and 376 species of mammals -- all of which are predicted to have a high increase in their risk of extinction.

Among them are species whose fates will be particularly dire, such as the Lombok cross frog (Indonesia), the Nile lechwe (South Sudan), the pale-browed treehunter (Brazil) and the curve-billed reedhaunter (Argentina, Brazil, Uruguay) which are all predicted to lose around half of their present-day geographic range in the next five decades.

Species living in Central and East Africa, Mesoamerica, South America, and Southeast Asia will suffer the greatest habitat loss and increased extinction risk, researchers.

However, they cautioned the global public against assuming that the losses are only the problem of the countries within whose borders they occur.