A new study has revealed Magellanic penguins as among the most faithful lovers in the animal kingdom.
Researchers, who followed the birds for 30 years using satellite-tracking system, found that a Magellanic penguin couple remained loyal to each other over a 16-year period, in spite of spending thousands of miles apart during their winter trips.
The researchers placed metal identity bands on the flippers of 50,000 birds on the southern coast of Argentina.
Previously penguin relationships were believed to span a maximum of just 10 years, with many cut short by the unexpected death of birds during migration.
But biologists were surprised by the longevity of the relationship between a particular couple, according to The Sunday Telegraph.
"The bond they have is incredible really," the Daily Mail quoted lead researcher Dr Pablo Garcia Borboroglu, of the National Research Council of Argentina, as telling the newspaper.
"It is unbelievable how far Magellanic penguins swim - and each breeding season they come back to the same nest and to the same partner," Borboroglu said.
The finding was revealed during a lecture to the Whitley Fund for Nature in London.
Dr Borboroglu will also release his findings in a book to be published next year called Penguins: Natural History and Conservation.