Ms Heathman said that scientists are now awaiting test results from more of the island’s penguins and are “preparing for a large-scale outbreak” of bird flu.
The newly recorded deaths confirm for the first time that gentoo penguins are susceptible to the disease. While gentoos do not have a yearly migration cycle like other penguins, experts say they could serve as a local reservoir of infection.
Scientists have been nervously watching H5N1, which largely spreads between birds but can also be transmitted by certain mammal species, travel down South America for months.
Last year, an outbreak of bird flu killed 220 flamingoes in north-western Argentina, along with 100,000 boobies and 85,000 cormorants in Peru. Some 17,000 elephant seal pups have also died from the disease in Patagonia in recent months.
In October, The Telegraph reported that bird flu had been detected for the first time in Antarctica, a critical breeding ground for more than 100 million birds, as well as seals and sea lions. The cases were found among brown skua on Bird Island.
Hundreds of thousands of penguins gather in tightly packed colonies on the Antarctic continent and nearby islands, which could enable the deadly virus to easily jump between animals.
“Some of these colonies are very dense, and when it takes hold it can spread quickly,” said Dr Norman Ratcliffe, a seabird ecologist with the British Antarctic Survey, at the time.