Speaking a Familiar Tongue
Study finds northern fur seal pups recognize mom's voice
When your mom calls on the phone, she doesn't have to identify herself. The sound of her voice is immediately familiar--even if you haven't seen her for months. Can other animals recognize the sounds made by their kin without seeing them, even after long absences? It seems likely, but until lately there has been little evidence to prove it.
A new study of northern fur seals on Alaska´s Pribilof Islands provides such proof. Stephen Insley, a biologist until recently with the Smithsonian Institution, found that seal pups recognize and respond to the tape-recorded calls of their mothers (and vice versa) after months or even years of separation.
The seals live in the cold waters of the North Pacific and haul out on remote beaches in the Pribilofs and elsewhere to breed in the summer. Female fur seals, unlike most other mammals, leave their nursing offspring for days at a time and go off to fish. On returning, they must find their pups among hundreds of other young seals wedged together at the breeding colony.
"The need for vocal recognition is a matter of life and death during that period," says Insley. Mothers and pups also use sight and smell to help identify each other, but each animal has a distinctive call (for pups, a lamblike bleat) that sets it apart from its cohorts.
By marking seals, recording their calls and playing them back during subsequent summers, Insley discovered that the animals remember their kins' calls, even after four years. He's not sure why the seals retain the memories for so long. For long-distance phone calls, perhaps?