London: Some seals can
point out on the spot they had been born even after spending five
years out at sea, a study reveals.
Antarctic fur seals', arguably the most accurate of any sea
mammal, has a remarkable instinct that allows them to return to
the spot where they were born to give birth to their own pups.
Nearly four million of the sea mammals breed in huge colonies on
the beaches of South Georgia in the southern Atlantic every year,
the journal of Mammalian Biology and Planet Earth Online reported.
After being born, the seals spend five years out at sea feeding
before returning to the island to breed, the Telegraph said.
While the Global Positioning System (GPS), which use satellites
orbiting the earth, can pinpoint a location to an accuracy of
around 15 feet, the seals were found to be accurate down to as
little as six feet.
This feat has baffled scientists, but they believe the creatures
use a kind of internal compass that helps them find their way
across the Southern Ocean to the correct location on the beach.
Using radio tags placed on 335 seals shortly after they were born,
researchers at the British Antarctic Survey have discovered that
each seal returns to exactly the same location on the beach once
they start breeding year after year.
"We don't know exactly why but it is common among sea birds and
other marine mammals to breed in large colonies. Antarctic fur
seals are among the most site faithful, on an average female seals
were giving birth to their pups to within 12 metres of where they
were pupped themselves. Some individuals returned to within one
body length of where they had been born," said Jaume Forcada,
scientist who led the study.
"It is surprising as these seals can travel really long distances
- they go up as far as Uruguay and down as far as the Antarctic
peninsula, we don't have any evidence of a navigation system yet,
but there must be something really, really strong that brings them
back to the same spot," she said.