The 150,000 penguins feared to have died after a giant iceberg left their colony in Antarctica effectively landlocked could be alive and well and living elsewhere, a scientist has suggested.

The Adélie penguins were presumed to have perished after their colony shrank drastically following the arrival of an iceberg the size of Rome close to their habitat in Cape Denison.

The grounding in 2010 of the B09B iceberg forced the birds to walk 60km from the colony to the coast to fish for food and 60km back again.

Australian scientists who had been monitoring the colony published a paper suggesting the birds had died after they witnessed the population drop from from 160,000 in 2011 to just 10,000 in 2015. The researchers from the University of New South Wales, who also reported seeing dead penguins in the vicinity, predicted that in 20 years the colony would be gone.

However, there is fresh hope that the penguins might be alive and living out their days in nesting sites.

Michelle De La Rue, a penguin population researcher at the University of Minnesota in the US, said the birds could simply have waddled off to join other penguins closer to the water. A similar phenomenon took place in 2001 when penguins on Ross Island relocated when an iceberg cut off their access to the sea.

“Just because there are a lot fewer birds observed doesn’t automatically mean the ones that were there before have perished,” LaRue, who was not involved in the original study, told Live Science. “They easily could have moved elsewhere, which would make sense if nearby colonies are thriving.”

However, scientists still know little about how the penguins emigrate between colonies and, ultimately, the fate of the penguins remains a mystery.

“I do not know what happened to these birds, but no one does for certain,” La Rue said.