Elephant seals, when they aren't basking in the sun or breeding on beaches, like to go the distance, traveling farther than previously thought when they are in the water, according to new research.

These massive marine mammals spend 90 percent of their lives in the deep ocean, and yet their elusive nature has kept their activities a mystery.

Back in the 1800s, elephant seal populations were down to as low as 30 individuals. The species was even declared extinct three times, but managed to make a miraculous comeback, first landing at Año Nuevo Island in 1957. About a decade later, the seals started colonizing mainland beaches, with the island's first pup born in 1976. Since then, these colossal creatures have made the trek to Año Nuevo to breed.

And with elephant seals being more abundant these days, biologists can more easily study their underwater habits and shed light on this little understood species.

"We're trying to figure out what these animals are doing at sea," Patrick Robinson, reserve director for the Año Nuevo UC Santa Cruz Natural Reserve, told San Jose Mercury News.

Researchers from the University of California (UC) Santa Cruz recently tagged and tracked elephant seal movement in the open ocean, using miniature cameras to learn more about their diet and environment. What they found was that male elephant seals spend most of their time in the northern Pacific, along the coast of Alaska and the Aleutian Islands, while females favor areas in the northeast Pacific.

However, some of these females travel even farther than expected.

"We even had two of them crossing the international date line last year, and we're not sure why," Robinson said. "At that point, they were closer to Russia than the US."

There are two species of elephant seals: the northern and southern. The northern elephant seals, which the UC Santa Cruz team studied, are found in California and Baja California. Meanwhile, southern elephant seals prefer frigid Antarctic waters that are rich in the fish, squid and other marine prey these seals enjoy, National Geographic reports.

Hunted for their oil, elephant seals have been on the brink of extinction many times. Luckily, there are around 225,000 to 230,000 elephant seals today, according to estimates.

And with elephant seals frequenting Año Nuevo during their breeding season, scientists have an opportunity each year to study these beasts up close and personal as they return to their true home in ocean waters.

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