Almost one-quarter of the world’s largest penguin colony population has been lost due to ‘climate-driven changes’
By
A study by researchers from the British Antarctic Survey (BAS) found that a remote volcanic island near Antarctica, formerly home to the world’s largest penguin colony, has experienced massive population declines in chinstrap penguins.
More than half a million chinstrap penguins have been lost from the Antarctic island of Zavodovski in the South Sandwich Islands, representing more than one-quarter of the island’s penguins. The penguin population there is made up mostly of chinstrap and macaroni penguins.
‘This is a worrying decline for chinstrap penguins, which have specialist diets and specific ocean temperature preferences,’ said Professor Norman Ratcliffe, a penguin ecologist at BAS.
‘Our tracking data show they prefer to forage in cooler waters to the northwest of the island, where they would expect to find Antarctic krill – the prey that make up the bulk of their diet. The problem is that, as waters warm, the krill have moved southwards into the Weddell Sea. Sea-ice cover to the south and a lack of suitable islands for nesting prevent chinstraps from following the food.’
Check out our related reads…
The new study, published on 7 October, found that Zavodovski Island now has the highest rate of chinstrap population decline out of anywhere in the world. Researchers attribute this steady loss to climate-driven changes in the Southern Ocean that disrupt penguins’ food supply.
To reach Zavodovski Island, located more than 2,000 kilometres from the nearest permanent human settlement, the BAS research team sailed for 15 days to the volcanic island, which is around twice the size of Gibraltar.
While camping there, they used drone surveys, aerial photography and tracking devices fitted to penguins to monitor them and understand the population. By comparing aerial surveys with satellite records, the team found a 63 per cent decline in occupied chinstrap nests from 2011 to 2025.
The South Sandwich Islands are home to 30 per cent of the world’s chinstrap population, so declines in their population – coupled with declines seen elsewhere in Antarctica – could tip chinstrap penguins into the IUCN’s ‘Endangered’ category.
While the chinstrap population declined, the macaroni penguin population increased by 28 per cent from 2011 to 2016. Unlike chinstraps, macaroni penguins can switch to alternative prey when krill becomes less abundant, so their populations are less affected.
Researchers remain concerned that such large changes to the chinstrap and macaroni populations could disrupt marine food webs across the region.
‘Our study is another example of a warming climate impacting even the most remote parts of our planet. The South Sandwich Islands are far from any humans, home to almost a third of the world’s chinstrap penguins – but not even they can escape the impacts of climate change,’ said BAS researcher Peter Fretwell.
