At a time when humpback whales are typically returning to Hawaii from Alaska, researchers are noticing they are doing so more slowly.

According to The Associated Press, the Humpback Whale Marine Sanctuary in Hawaii reported the dip in whales returning for the winter. Ed Lyman, a resource protection manager and response coordinator with the sanctuary, opined the low numbers of humpbacks may not be a bad thing.

"This isn't a concern, but it's of interest. One theory was that something like this happened as whales increased. It's a product of their success," Lyman told The AP. "What I'm seeing out there right now I would have expected a month ago.

"We've just seen a handful of whales."

The Christian Science Monitor reported in Sept. that humpback whales were spotted in the Long Island Sound for the first time in some 20 years. A study from two wildlife organizations in 2007 indicated warming oceans were causing whales to alter their migrations.

The humpbacks who are slow to return to Hawaii may fit the bill, as the researchers believe they are still feeding in Alaskan waters. Additionally, if the whales are successful in increasing their numbers there would be more mouths competing for food. As a result, more whales do not eat enough to store enough energy for the migration, The AP noted.

"They also may not stay here as long, especially the males," Lyman told West Hawaii Today. "They may not have energy reserves."