If sea ice in the Antarctic continues to melt at its present rate, the spectacular Emperor penguin will face extinction near the year 2100. Placing the species on the US Endangered Species List may be our only chance to save these magnificent birds.
A new study that combines deep knowledge of penguin biology with sophisticated computer modeling shows the penguin's options over the next 80 years are dwindling. Despite the species' ability to choose from many migration options, they simply may not be able to solve the problem of survival.
Emperor penguins are the largest of all penguins, with adults often exceeding 3.5 feet in height. Their stately, waddling gait, the intense care for their young, and their ability to thrive in the harsh icy Antarctic are the subject of legend. With black backs and white fronts tinged with orange, they have all the tuxedo-clad splendor any regent would desire.
A primary ecological factor in the survival of these beautiful birds is their relationship to sea ice. They thrive in precisely balanced situations, where the sea ice is enough for a colony to live and breed but not so much sea ice that they must walk long distances to get to open-water feeding grounds.
Many studies of the 54 colonies at Pointe Géologie reveal that the penguins have a remarkable ability to migrate to optimum habitats. These are not inflexible movements. The penguins seem to consider changing ecological factors as they make collective decisions to move from place to place.
Woods Hole Oceanographic Institutions' (WHOI) penguin specialist Stéphanie Jenouvrier teamed up with French mathematician Jimmy Garnier from the University of Savoy Mont Blanc. With Jenouvrier's knowledge of biology and Garnier's computer modeling skills, they asked this question: Of all possible migration options, what are the penguins best chances for survival?
The team modeled changes in ecological conditions and possible colony responses, including dispersal stages, distance traveled, what habitats were available, and rates of density-dependent dispersion.
The results show that optimal choices resulted in stable population rates through 2036, followed by an ecological rescueperiod. But after 2046 the penguin's options begin to decline. The model suggests that no matter what strategy the penguins employ, no matter how they disperse or where they go their numbers will be reduced to 40-99% of present levels by 2100. After that, extinction is a possibility.
A solution? Jenouvrier and her colleagues suggest that the US government place the Emperor penguin on the Endangered Species List and use all the ESA's legal powers to protect the colonies. The team argues that every possible computer model shows that with the current warming trends there is no scenario by which these penguins can save themselves. Human protection is needed.
For these birds, the options are running out.