Of the approximately 88 species of Cetaceans in the world (there is some disagreement on the actual number), researchers have seen 24 different species in the waters surrounding Hawaii. Most people who come to Hawaii to whale watch are looking for Humpback whales - but we commonly see Spinner Dolphins, and occasionally see Spotted Dolphins, Bottlenose Dolphins and even more rarely, smaller toothed whales like False Killer Whales and Melon heads.
Why are Humpback whales called “Humpback?”
The Latin name for a humpback is ”Megaptera novaengliae” which means “big-winged New Englander” referring to their exceptionally long pectoral fins. We call them “humpbacks” because when these whales begin their breath hold dives, they roll their backs making a little hump as they dive.
When do Humpback whales arrive in Hawaii and when do the leave?
We start seeing stragglers around the Waikoloa area as early as the end of October. By December, there are enough individual whales around to run whale watch cruises. By the middle of April, most whales have begun their migration away from the islands, and by mid-May, it’s rare to see an individual humpback.
Where do they migrate from, and where do they go back to?
The humpbacks that winter in Hawaii are part of the North Pacific stock. They spend their summers off the Southern shores of Alaska and the Aleutian Islands.
Why do they come to Hawaii?
Researchers believe that humpbacks migrate to areas where the water temperature is about 75 degrees Fahrenheit, the water depth is less than 600 feet, and the surface conditions are generally calm in order to calve successfully. Humpbacks are pregnant for about 10 ½ months, so their mating season is in the winter too, which explains the presence of the male whales. By the way, not all of the North Pacific humpbacks winter in Hawaii - we see between 50% and 60% of the population here during the winter. The rest of the population winters near Baja, California, or the Southern Islands of Japan.
How many Humpback whales are there?
Population estimates vary, but according to recent research conducted by over 400 researchers taking part in the SPLASH project (Structure of Populations, Levels of Abundance and Status of Humpbacks) the North Pacific population now numbers somewhere around 18,000 - 20,000 animals. Researchers believe that the population is growing by about 7% each year in the North Pacific.
Are Humpback whales protected at all?
YES!! In 1966, the International Whaling Commission placed humpbacks under protection in the North Pacific. In the United States, the National Marine Fisheries Service enforces regulations designed to protect humpbacks as designated by the Marine Mammal Protection Act of 1972, and the Endangered Species Act of 1973. Basically, vessels, swimmers and divers cannot approach a humpback within 100 yards, herd or drive them from any distance, separate a cow from her calf, or “substantially disrupt the normal activities of a humpback.” Aircraft must stay more than 1000 feet above the whales.
How big are Humpbacks?
The fifth largest of the great whales, humpbacks average about 40 - 45 feet long when they are fully grown and can weigh up to one ton per foot. Females are slightly larger than males. Calves are 10 - 15 feet long at birth and weigh about 3000 pounds.
What do Humpbacks eat?
Humpback whales don’t have teeth - they’re baleen whales. Baleen is actually a fringy plate made of keratin (the same stuff your toenails are made of), and they use those plates to strain the ocean of small fish, copepods (a small crustacean) and krill (a type of shrimp). A fully-grown whale can eat more than a ton of food per day in Alaska (that’s about a million and a half calories every day!), but in Hawaii, they don’t eat anything. They live off of their stored fat (blubber). Baby whales, of course, drink their mother’s milk (about 50 to maybe as much as 100 gallons each day).
