April 4, 2013
Antarctica’s Adelie Penguins May Benefit From Global Warming
Brett Smith for redOrbit.com - Your Universe Online
While some may be lamenting the impending forces of climate change, AdÃ©lie penguins could actually benefit from rising global temperatures.
According to a new study in the open-access journal PLoS ONE, the AdÃ©lie penguin population on Antarctica´s Beaufort Island increased 84 percent as the region´s ice fields retreated from 1958 to 2010.
"This research raises new questions about how Antarctic species are impacted by a changing environment," said co-author Michelle LaRue, from the University of Minnesota´s College of Science and Engineering (CSE). "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 AdÃ©lie penguins or other species."
Along with a team of American and New Zealand researchers, LaRue based her findings on aerial and satellite imagery dating back more than 50 years along with weather data collected from McMurdo Station in Antarctica.
The imagery revealed drastic changes to the Antarctic landscape. The research team found that the available habitat for the penguins´ colony on Beaufort Island increased by 71 percent since 1958, with the biggest increase (20 percent) from 1983 to 2010. While the snow and ice field to the north of the main colony did not shift from 1958 to 1983, it has retreated over 1,750 feet from 1983 to 2010.
The penguins´ population growth coincided with this expansion of new habitat. In addition to the overall growth in their numbers, researchers also saw an increase in population density, even as the colony filled in what used to be covered by snow and ice.
As a partial explanation of the colony´s growth, the team found that emigration rates of birds from Beaufort Island to nearby Ross Island decreased after 2005.
"We learned in previous research from 2001-2005 that it is a myth that penguins never move to a new colony in large numbers. When conditions are tough, they do," explained co-author David Ainley, a senior marine wildlife ecologist with environmental consulting company H.T. Harvey and Associates. "This study at Beaufort and Ross Islands provides empirical evidence about how this penguin attribute will contribute to their response to climate change."
The researchers referred to aerial imagery to determine changes in available nesting habitat, but they also studied penguin feces and urine stain patterns to determine the available habitat.
"This study brought together researchers from different academic disciplines who all contributed their expertise," LaRue said in a statement. "We had people who study climate change, spatial analysis, and wildlife population dynamics. This is how good science leads to results."
According to the researchers, they plan to expand their methods to look at other nearby AdÃ©lie penguin populations to gain a better grasp on how climate change is affecting the regional population.
AdÃ©lie penguins primarily inhabit the southern Antarctic coast. Smaller than their Emperor penguin counterparts, at about 10 to 12 pounds, the AdÃ©lie penguin only live near sea ice; but needs the ice-free land to breed. Breeding penguins produce about one chick per year and return to the same area to breed if conditions have remained the same.