Warming temperatures forcing an upward shift

from Cornell Lab of Ornithology

The Russet-crowned Warbler was the most common bird at the ridgetop in 1985. Though still present, the population has declined by an estimated 72 percent. Photo by Graham Montgomery.

Warmer temperatures are pushing mountain-dwelling birds ever higher as they try to stay in their comfort zone. That’s the conclusion of a group of scientists who retraced the steps of a 1985 expedition in the Peruvian Andes and documented how birds had shifted in the intervening 30 years.

The new study also shows that species that were already living on the ridge-top now have smaller ranges and some have disappeared altogether compared with the 1985 survey. The study, by University of British Columbia and Cornell Lab of Ornithology scientists, appears in Proceedings of the National Academy of Sciences. “Mountaintop species are running out of mountain,” says Benjamin Freeman, lead author and postdoctoral fellow at the University of British Columbia. “The next step is extinction. Of the 16 mountaintop species found in the last survey, 8 are missing from our new survey.”

Full release at https://mailchi.mp/cornell/release-survey-finds-mountain-birds-are-on-an-escalator-to-extinction-1313445