Environment
1:10 pm
Tue December 27, 2011

Climate Change Forcing Tropical Bird Migration

Deep-blue Flowerpiercer

A new study out of Duke University finds global warming is forcing tropical birds in Peru to migrate to higher elevations. But it also finds they're migrating at a slower rate than the world is warming.

Study author German Forero-Medina says they used data collected 40 years ago by a Duke professor in the region.

German Forero-Medina: "With this information, we were able to compare the distribution of the species 40 years ago with the present distribution. And we were able to find that indeed species are moving uphill an average of 49 meters during the last 40 years."
Forero-Medina says that's about a third of the 150 meters expected from warming trends. He says that means the birds could be adapting to warmer temperatures. But it could also mean the birds are in danger of overheating and dying off. There's also the possibility the birds will eventually run out of habitat as they move up the mountain.

Forero-Medina: "[These birds] tend to have very small ranges, which makes them more vulnerable to threats, be that human threats or climate change or whatever... because the smaller the range, the higher the probability that something can go wrong within the range and the species can eventually go extinct. If warming continues, eventually they might run out of habitat. They are very close to the peak, which scientists call mountaintop extinction. If they are very close to the mountain, if they continue moving, they may run out of habitat."