January 27, 2009
Antarctica’s Emperor Penguin On Course To Endangerment
Immortalized by the blockbuster 2005 movie "March of the Penguins," the emperor penguin is in grave danger of becoming extinct before the end of the century, say Woods Hole Oceanographic Institution (WHOI) researchers.
Founded on predictions of melting sea ice from climate change numbers, the penguins will most likely see their figures dive by 95% by 2100.
The five researchers, including WHOI biologists Stephanie Jenouvrier and Hal Caswell, took mathematical models to calculate the outcome the climate change has on the penguins and the consequential loss of sea ice.
The research notes that if the sea ice continues to melt at the same rates available in the latest Intergovernmental Panel on Climate Change (IPCC), the population of a big emperor penguin colony in Terre Adelie, Antarctica, will decrease from its currant size of 3,000 to 400 by 2100. The probability of this happening, say researchers, is a one-in-three chance and maybe even eight out of 10.
Even though the penguins could avoid this catastrophe by changing their breeding habits, lead researcher Stephanie Jenouvrier thinks that this is unlikely.
"Unlike some other Antarctic bird species that have altered their life cycles, penguins don't catch on so quickly," she said. "They are long-lived organisms, so they adapt slowly. This is a problem because the climate is changing very fast."
A number of previous numbers have indicated that continuing climate change will distress their reproduction, but this is the first report that makes calculations about the overall fate of a species.
"I don't see any reason not to take these predictions very seriously," stated Dan Reuman, a biologist at Imperial College London. "The study is based on a wide range of climate forecasts, it takes a conservative approach, it's based on a large amount of data on penguin demography, and the model accurately forecasts the data that already exist."
This reaction is echoed by Joel Cohen, leader of the Laboratory of Populations at Rockefeller University.
"The emperor penguin is an important species in its own right, but the whole communities in which it's embedded are also of importance," he said to BBC News.
The penguins are the main species that draws media attention to the continent, he added. "They are to Antarctica what the polar bear is to the Arctic," Cohen said. "This study takes our knowledge, puts it together, gives us some insights, arouses concern and suggests that we ought to be understanding this situation a lot better."
Emperor penguins, the biggest species of penguins, are distinctive in that they are the only kind that mates in the brutal Antarctic winters. They make extensive marches across the sea ice, where the females lay only one egg that is cared for by the male. That means that the ice plays a major role in their overall breeding success.
The impending loss of sea ice also affects the quantity of krill and other kinds of fish, which are major food sources for the penguins.
"The key to the analysis was deciding to focus not on average climate conditions, but on fluctuations that occasionally reduce the amount of available sea ice," said Hal Caswell, who is noted for his work in mathematical ecology.
"Unlike some other Antarctic bird species that have altered their life cycles, penguins don't catch on so quickly," Jenouvrier said. "They are long-lived organisms, so they adapt slowly. This is a problem because the climate is changing very fast."
The research was a group effort between WHOI, led by Caswell, scientists from Expeditions Polaires Francaises and Institut Paul Emile Victor, and scientists from the National Center for Atmospheric Research and the National Snow and Ice Data Center.
"The project was truly interdisciplinary," said Jenouvrier, "which is critical for this kind of research."
In the future, the study could create legal regulations for the emperor penguin. In December, the U.S. Fish and Wildlife Service released a ruling refusing to list the emperor penguin under the Endangered Species Act. This decision is still being reviewed and the findings presented in this paper will be considered.
On the Net:
- Woods Hole Oceanographic Institution
- Intergovernmental Panel on Climate Change
- Imperial College London
- Rockefeller University