Mystery absence of humpback whales in Hawaii has experts scratching heads

The giant whales, who usually spend the period from November through May in the area, are a well-known part of winter but have been slow to return

Humpback whales have been slow to return to Hawaii as December usually marks the start of the season, experts say.

The giant whales are a famous part of winter on the islands and a source of income for tour operators. But officials at the Humpback Whale Marine Sanctuary said they've been getting reports that the whales have been difficult to spot so far.