The season for penguin researchers is drawing to a close again, as it does year after year, on a remote island off the coast of Antarctica. Two Australian Antarctic Division field biologists, Kim Kliska and Marcus Salton, have been living on Béchervaise Island for three months, continuing a three-decade long-term monitoring program.
Béchervaise Island is a center for seabirds in East Antarctica, Kim Kliska said. “It’s a fairly flat, open island with some sub-colonies of Adélie penguins. We also have skuas, snow petrels and Wilson’s petrels that breed here,” she says.
“For all seabirds, we are trying to understand how many individuals of each species breed and their breeding success. We want to know how many eggs they lay, how many chicks hatch and then how many fledge at the end of the season, which gives us a really good indication of population numbers.”
Marcus Salton points out that the long-term monitoring program on Béchervaise Island is “unusual and unique” because it spans three decades. “Thirty years is the lifespan of a penguin, so we can start to look at the things that happen in that time, such as changes in breeding success and how that relates to changes in their environment,” he says.
Two specially designed weighbridges on Béchervaise Island automatically weigh and identify the penguins and record data on the duration of foraging, time spent in the colony, and weight changes before and after foraging.
“Even when we’re not here, we get a lot of information about the individuals and we can watch how that changes over time in terms of breeding success,” Salton explains.
Penguins are an indicator species, and this research on Adélie penguins helps inform management of the krill fishery in the region. “We can look at how much krill they actually feed their chicks. From this, we can derive an estimate of how much they need and ensure that the krill fishery in the region also leaves enough food for the penguins,” Kliska said.
Biologists also use automatic surveillance cameras that take daily photos of the penguin colonies. But nothing beats the high-quality information obtained by physically counting penguins on the ground.
“We weigh the chicks, collect samples to learn about their diet, genetics and pollution, and attach transmitters to track the birds’ foraging movements and behavior,” Kliska describes.
The seabird research program, which also extends to the broader Mawson region, found the current number of Adélie penguins on all islands within 50 kilometers east and west of the station to be 120,000 breeding pairs. “Here on Béchervaise Island, we have about 1500 breeding pairs of Adelie penguins, so it’s only a small fraction of the larger regional population,” Salton says.
Source: Australian Antarctic Division