University of Washington biology Professor P. Dee Boersma and doctoral student Amy Van Buren wanted to determine how birds that swim rather than fly and live nearly exclusively in the Southern Hemisphere are discovered deep in the Northern Hemisphere.
The most probable explanation, said Boersma and Van Buren, is the birds were hauled aboard boats -- probably fishing boats -- in southern waters and were kept by the crews as the vessels traveled far to the north and then were released.
"The crews keep the penguins as pets on board the boat," said Van Buren. "People keep them around because they're so cute."
Added Boersma: "People have always tried to move species around, and that's particularly true for penguins because people like penguins. They're still regularly kept as pets in villages in Peru and Chile."
The biologists outline their research in the June edition of the Wilson Journal of Ornithology.