Pregnant female elephant seals journey for 240 days every year across the Eastern North Pacific Ocean about 6,200 miles (10,000 kilometers) away from home in search of food. Despite the distance, they still manage to return to their home beach in time for their pups' arrival.
New research reveals that elephant seals have map sense like a built-in GPS to help them get home within five days before they give birth. Roxanne Beltran from the University of California Santa Cruz said that migrating elephant seals know their breeding beach even if they are thousands of miles away and know how long it will take to get back.
Elephant Seal Breeding and Migration Seasons
Male elephant seals define and defend their territories when breeding season arrives, according to National Geographic. Males battle each other for mating dominance, which involves roaring and aggressive posturing that sometimes ends up n a violent and bloody battle. They collect a harem of 40 to 50 female elephant seals.
They give birth in late winter to one pup after 11 months of pregnancy and nurse it for a month, wherein the female does not eat during that entire time as both mother and child live off the energy stored in her blubber.
Migration helps them store this amount of energy as they spend months at sea searching for food, often diving deep to forage. They only return when it is time to breed and give birth. Although males follow a consistent route during migration, females do not precisely follow a consistent route because they pursue moving prey.
Elephant seals were once reduced to the brink of extinction in terms of population because they are aggressively hunted for their oil. But fortunately, their population has increased once again under legal protection.
ALSO READ: Photobomber of the Year: Diver Gets Unexpected Cuddle From Seal Underwater
Elephant Seals Have Built-In GPS
Scientists have long known that elephant seals are expert navigators. However, it remains a mystery how they manage to make it back to the beach in time for breeding and birthing season.
In the new study, titled "Elephant Seals Time Their Long-Distance Migrations Using a Map Sense" published in the journal Current Biology, scientists used satellite tracking data from 100 adult female elephant seals to find out how they go back to their home beach in time to give birth.
Dr. Beltran and her colleagues found that elephant seals know how far they are from their breeding beach and how long it will take to get back, Science Daily reported. It allows them to adjust the timing of their travels based on a complex internal perception of space and time.
Furthermore, the data revealed that the decision to turn around was not related to their body condition or the amount of body fat. Beltran said that they expected that highly successful or fatter seals might end their foraging journey earlier, but they were surprised to find that it was not the case.
Instead, it seems like a map sense is programmed in them that tells them to turn around strategically based on where they are and, in turn, how long it will take to get them back to their home beach. The team has not yet identified what sensory cues the elephant seals spend on to track their location, but the data clearly shows that the timing of their travels is based on their built-in GPS.
Check out more news and information on Elephant Seal in Science Times.