During their stay in Hawaii, they do not feed, but rely upon energy stored in their blubber. Instead of feeding, the whales devote most of their time to mating and bearing their calves.
Another interesting behavior exhibited by the humpbacks during their stay in the islands is singing. The "songs" of humpbacks are made up of complex vocal patterns. All whales within a given area and season seem to use the same songs. However, the songs appear to change from one breeding season to the next. Scientists believe that only male humpbacks sing. While the purpose of the songs is not known, many scientists think that males sing to attract mates, or to communicate among other males of the pod. http://earthtrust.org/wlcurric/whales.html
How humpbacks create these sounds is unknown since they do not have functional vocal cords. Last week my wife was kept awake at night by the sounds of the whales that sounded like haunting cries and others that had a trumpeting sound.
The Hawaiian Islands Humpback Whale National Marine Sanctuary was created by Congress in 1992 to protect humpback whales and their habitat in Hawai`i. The sanctuary, which lies within the shallow (less than 600 feet), warm waters surrounding the main Hawaiian Islands, constitutes one of the world's most important humpback whale habitats.
By the way, does anyone still call Wednesday, “Happy, happy hump day?”