This year experts say Hawaii’s returning humpback whale population has dwindled compared to previous years. Typically, the whales migrate en masse from Alaska to Hawaii during the period of time between November and May in order to take advantage of the warmer weather.
According to Time, the whales are returning far more slowly than usual. An estimated 10,000 whales make the journey from Alaska to Hawaii each year, though recent data indicates that fewer whales have returned so far than were expected.
“What I’m seeing out there right now I would have expected a month ago,” said Ed Lyman, a response coordinator for the sanctuary, during an interview with the Associated Press.
El Nino, which has created warmer temperatures in the Pacific Ocean, might be able to explain Hawaii’s current dearth of whales. If the waters in Alaska are already warm enough to live in comfortably due to El Nino, it might be enough to encourage whales to stay put rather than make the extensive journey to Hawaii.
Another potential explanation posits that the lack of whales in Hawaii actually means there has been an increase in the overall population. Should the whale population have increased in between this years migratory period and the last’s, then it might make sense for the whales to transition between Alaska and Hawaii more slowly.
“One theory was that something like this happened as whales increased,” said Lyman.
“It’s a product of their success.”
A larger population of whales would require more food. Perhaps traveling as a pack would mean there simply would not be enough food to go around, rendering it a bad idea to migrate as quickly as they might have in years passed.