Global warming proves helpful for penguins

MINNEAPOLIS, April 4 (UPI) -- Not all species are threatened by climate change; Adelie penguin numbers are in fact increasing as warming makes antarctic ice fields retreat, researchers say.

An international science team led by University of Minnesota researchers reports the population size of an Adelie penguin colony on Antarctica's Beaufort Island near the southern Ross Sea increased 84 percent as the ice fields retreated between 1958-2010, with the biggest change in the last three decades.

Using a mix of old and new technology -- aerial photography beginning in 1958 and modern satellite imagery from the 2000s -- the researchers say they estimate the population increased from 35,000 breeding pairs to 64,000 during the study period.

In addition to the overall population growth, researchers noted an increase in population density as the colony filled in what used to be unsuitable habitat covered in snow and ice.

Adelie penguins, common along the southern antarctic coast, live only where there is sea ice but need ice-free land to breed.

"This paper encourages all of us to take a second look at what we're seeing and find out if this type of habitat expansion is happening elsewhere to other populations of Adelie penguins or other species," Michelle LaRue of Minnesota's Polar Geospatial Center said.