The first comprehensive survey of a key Antarctic penguin breeding area in 50 years has revealed a drastic decline in the population of chinstrap penguins.
In January and February 2020, Noah Strycker at Stony Brook University in New York and his colleagues carried out a census of penguin populations on Elephant Island, which is part of the South Shetland group of Antarctic islands.
They found that the population of chinstrap penguins on the island has declined by 57 per cent since the last complete survey conducted in 1970鈥�71.
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鈥淭his particular region, the Western Antarctic peninsula, has warmed up disproportionately in the past several decades,鈥� says Strycker. 鈥淲e鈥檙e starting to see changes that are probably associated with that warming trend, both environmentally and in terms of the populations of the animals that live there.鈥�
The researchers spent 12 days surveying penguin populations, both on the ground on Elephant Island and using drones. They identified 53,087 breeding pairs of chinstrap penguins at 29 breeding locations, which the animals return to each year.
The population of other penguin species, however, has increased: gentoo penguins on the island have doubled in number since 1970, and the team also found more king penguins than in the previous survey.
Both these species are also found in sub-Antarctic regions farther north. 鈥淎s things warm up and there鈥檚 less ice around, they can still survive and find the food that they need, so they are expanding southward,鈥� says Strycker.
鈥淯nlike the other penguin species, Elephant Island is the core stronghold of the chinstrap penguin鈥檚 range,鈥� says Strycker.
While chinstrap penguins are still the predominant species on the island, the declining population may presage changes that could be seen farther south with ongoing warming.
鈥淭he indications are that climate change is having a huge impact on this region in terms of everything from sea ice cover, to where krill concentrates, to how penguins are able to make their migrations offshore during the winter,鈥� says Strycker.
Polar Biology
