The bodies of hundreds of birds native to the North Sea have washed up on the east coast of England.
The Fulmar can live for 45 years
Wildlife experts are now desperately trying to find out why the female Fulmars, a relative of the albatross, are dying young.
Alison Charles, of the RSPCA, said: "We think they're all starving. Preliminary post mortems suggest they're starving to death."
About 150 birds have been brought in and only three were still alive.
Ms Charles told BBC Look East it was assumed the birds were suffering because of a shortage of fish to eat, and not because of environmental pollution.
She said the RSPCA was sending out laboratory samples and consulting experts, but that no traces of poisons had been found in the birds taken to the RSPCA centre at East Winch in Norfolk.
Steve Bexton, a wildlife veterinarian, said: "Interestingly, all the birds have been female.
"We know the female birds spend the winter further out to sea than the males do, so whatever is affecting the birds is taking place out in the North Sea rather than near the coast."
Some, like Adam Rowlands with the RSPB, think northerly gales might have simply blown Arctic Fulmars off course.
He said: "It may be there are some extreme weather conditions, which have given Fulmars difficulty in finding food, and that, in combination with strong northerly gales, has blown them into the North Sea and unfortunately caused birds to starve."
Mr Bexton said: "It's still a mystery. We don't know what is going on."