Scientists say female Antarctic fur seals have an "uncanny" sense of geography. And that GPS-like sense helps them return to within a few feet of their birthplaces when it's time to deliver pups of their own. The researchers' study, published in Mammalian Biology, also found that mothers tended to get closer to the precise spot of their birth every time they came home. Here, a brief guide:

How close to their birthplaces do these seals get?
Very close. Some female Antarctic fur seals have managed to give birth within a body length of the spot where they were born. Most have their pups within 40 feet of their own birthplace. "It's as if they have some sort of in-built GPS system," study leader Joe Hoffman, from the University of Bielefeld in Germany, tells Planet Earth.

Why is that so surprising?
The animals sometimes spend five years wandering hundreds of miles away out to sea before returning home for the first time. For instance, one male was found this year on the beach in Gabon, 2,800 miles away from the nearest Antarctic fur seal colony.

Where do they give birth?
Some 97 per cent of the world's Antarctic fur seal population lives in south Georgia in the south Atlantic Ocean. The cobblestone beach these scientists watched, on Bird Island in south Georgia, had 600 females and 200 males crammed into a space half the size of a football field.

Are these seals really so unique?
Not entirely. Previous studies found that other marine animals, including other seals, sea lions, and walruses, also return to the colonies where they were born when it's their time to breed. Female gray seals at North Rona and the Isle of May in Scotland were observed picking sites within 100 yards of where they were born to have their pups. And wherever they elect to give birth, seals tend to return to the same spot year after year.

Sources: Planet Earth, Mongabay, National Geographic