More birds face extinction this century

WASHINGTON – About 10 percent of all bird species face extinction by the end of the century and 15 percent more are on the brink, according to researchers who say such extinctions would have a widespread effect on the environment, agriculture and human society.

“Important ecosystem processes, particularly decomposition, pollination and seed dispersal, will likely decline as a result” of the loss of bird species, said Cagan Sekercioglu of the Stanford University Center for Conservation Biology.

The forecast of Sekercioglu and colleagues was published online Monday by Proceedings of the National Academy of Science. The Stanford estimate was based on a year of study and a computer calculation of three possible scenarios.

The result was a forecast that between 6 percent and 14 percent of all bird species will be extinct by 2100, and 700 to 2,500 species will be critically endangered or extinct in the wild.

Birds pollinate many plant species and carry the seeds of others to new locations. This is particularly important in Australia, New Zealand and oceanic areas where pollination and seed dispersal by birds is more common, researchers said.

Another problem could occur with the loss of scavenging birds that help dispose of the bodies of large animals by consuming the flesh and leading other scavengers to the bodies, a process that helps limit the spread of disease from decomposing carcasses.

As an example, researchers noted that a sharp drop in the vulture population in India in the 1990s was followed by a jump in the population of rats and wild dogs, some of which spread rabies.

Birds also eat millions of insects, and a decline in birds could lead to a dangerous increase in damaging pests.