STANLEY (Falkland Islands) — A deadly type of bird flu has been found in gentoo penguins for the first time, according to the Scientific Committee on Antarctic Research (Scar), stoking concern that the virus could spread among Antarctica's huge penguin colonies.

Researchers found about 35 penguins dead in the Falkland Islands in the South Atlantic on Jan 19. Samples taken from two of the dead penguins came back positive for the H5N1 avian influenza virus, said Dr Ralph Vanstreels, a veterinarian who works with Scar.

The Falkland Islands government told Reuters that many more gentoos were dying under similar circumstances. As of Jan 30, "there are over 200 chicks dead alongside a handful of adults", said government spokesperson Sally Heathman.

The deaths confirm that gentoo penguins are susceptible to the lethal disease that has decimated bird populations across the world in recent months. However, gentoos rarely travel between the Falklands off Argentina's coast and the Antarctic Peninsula, which lies some 1,300km to the south.

That means travelling penguins are unlikely to drive the spread to the southern continent, said Dr Vanstreels, a researcher affiliated with the University of California-Davis.

"The role that gentoo penguins could have, instead, is to serve as local reservoirs of infection," he said. "That is, maintain a pool of susceptible hosts that never leaves the islands."

Ms Heathman said the Falkland Islands government was also awaiting test results from rockhopper penguins and "preparing for a large-scale outbreak".

In nearby South Georgia, authorities ruled out a report of bird flu suspected in king penguins after a detailed survey of the site, said Dr Meagan Dewar, who leads Scar's Antarctic Wildlife Health Network.

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 individuals.

Conservationists are more concerned about other species, Dr Vanstreels said. Elephant seals and fur seals have died in larger numbers from bird flu in South Georgia, following mass casualties in those species in South America.

"This is especially concerning because South Georgia is home to 95 per cent of the world's population of Antarctic fur seals. If that population collapses, the species will be in a critical situation," he said. REUTERS