Say goodbye to the birds.

Over the past half-century, North America has lost more than a quarter of its entire bird population, or around 3 billion birds.

That’s according to a new estimate published in the journal Science by researchers who brought together a variety of information that has been collected on 529 bird species since 1970.

“We saw this tremendous net loss across the entire bird community,” says Ken Rosenberg, an applied conservation scientist at the Cornell Lab of Ornithology in Ithaca, N.Y. “By our estimates, it’s a 30% loss in the total number of breeding birds.”

Rosenberg and his colleagues already knew that a number of bird populations had been decreasing.

“But we also knew that other bird populations were increasing,” he says. “And what we didn’t know is whether there was a net change.” Scientists thought there might simply be a shift in the total bird population toward more generalist birds adapted to living around humans.

But no; overall loss as well as shift.

Common birds with decreasing populations include meadowlarks, dark-eyed juncos, horned larks and red-winged blackbirds, says Rosenberg. Grassland birds have suffered a 53% decrease in their numbers, and more than a third of the shorebird population has been lost.

I think swallows must be another; they used to be abundant here in Seattle and now they’re not.

Oh well. There are lots of chickens now.