Polar bears have become the poster child for climate change, but at the opposite end of the globe another beloved animal is facing a major threat from the warming climate: penguins.
By the end of the century, 60 percent of the breeding habitat for Adélie penguins (Pygoscelis adeliae) could be too warm and too wet to host colonies, according to a new study in the journal Scientific Reports.
The study's lead researcher, Megan Cimino, combined data from 1981 to 2010 on Antarctic sea ice and ocean temperatures with satellite imagery and ground observation of penguin colonies. She was able to piece together how the penguin population has reacted to habitat and climate fluctuations over the last few decades.
Using that data and recent climate change models, Cimino and her colleagues were able to make predictions about future habitat for the Adélie penguins, which inhabit sites all over Antarctica. The news was not great. By 2060, 30 percent of the animal’s colonies will be in jeopardy, and 60 percent will be impacted by 2099.
Historical data shows that over the last 35 years some colonies remained stable, some grew, and some declined reports Aaron Sidder for National Geographic. The declines were mainly associated with areas that saw the largest changes in their normal climate or conditions.
Cimino highlights the extreme loss of penguins in a colony near the U.S. research facility at Palmer Station on the West Antarctic Peninsula (WAP), which has decreased by about 80 percent since the 1970s.
“Within this region we saw the most novel climate years compared to the rest of the continent,” she explains. “This means the most years with warmer than normal sea surface temperature. These two things seem to be happening in the WAP at a higher rate than in other areas during the same time period.”
As the climate changes, it will affect the penguins in two main ways. First, it will make many rocky nesting areas, which are normally cold and dry, too wet. “For penguins who lay their eggs on the ground … rain and puddles are bad because eggs can’t survive when they’re lying in a pool of water,” Cimino tells Sidder. “Chicks that don’t have waterproof feathers can become wet and die from hypothermia.”
Second, changing sea temperatures will reduce the fish that the penguins rely on. Cimino tells Sidder that researchers have already seen reduced fish populations in some areas, forcing the penguins to subsist mainly on krill.
While the polar birds are likely to take a heavy hit, Cimino says the research also found a few strongholds where the species has been able to weather challenges in the past and that may help them survive the coming crisis.
“The Cape Adare region of the Ross Sea is home to the earliest known penguin occupation and has the largest known Adélie penguin rookery in the world,” she says in the press release. “Though the climate there is expected to warm a bit, it looks like it could be a refugia in the future.”