Learn about Hawaii's Humpbacks

Humpbacks 101

What kind of whales can I see in Hawaii?
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 Humpbacks 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 it’s mating season in 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 – 22,000 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. As of October, 2016, the Humpbacks who winter in Hawaii (and 8 of the other 14 distinct populations of Humpbacks around the world) will no longer be listed on the Endangered Species List!

How big are Humpbacks?
The fifth largest of the great whales, humpbacks average about 45 – 50 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 900 pounds of food per day in Alaska (that’s about a 560,000 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).

How long can Humpbacks hold their breath?
A fully-grown humpback can hold her breath as long as 45 minutes. But usually, in Hawaii they don’t.  An average breath hold dive in Hawaii is about 10 – 15 minutes. And a calf can only hold his breath for a few minutes.

How do Humpbacks spout?
Humpbacks exhale through two blowholes on the tops of their heads (they inhale through the same blowholes). A humpback exhales very forcefully – blowing out 90% of the volume of his lungs in half a second at about 300 mph. Some researchers believe we can see the spout because the exhalation contains moisture from the whale’s lungs that is atomized under pressure. Other researchers believe we are actually seeing atomized mucus (a 15 foot tall spray of boogers).

Why do whales splash around so much on the ocean’s surface?
Since we can’t ask the whales, all we can do is speculate. Some researchers believe that the big splashes serve as an attention-getting device – perhaps a way to demonstrate size, and health. It may be a way to express aggravation or aggression. It may be a way to knock unwanted skin parasites off.  Or it might just be fun – it might feel good.

Do Humpbacks have any other ways to communicate besides splashing?
Humpbacks are very vocal creatures. While feeding, they do make a lot of grunting and squeaking noises, but it is during mating season that the most complex communication takes place. In 1967 researchers listening to sounds made by humpbacks realized that the sounds are not random – they’re actually organized into repeating patterns that we call songs. Since then, researchers have observed that only male whales sing these songs, but the same version is sung by all the males in a breeding location. The songs evolve from season to season, never exactly repeating themselves. We don’t know the reason for these complex songs, but it has been observed that female whales don’t approach a singer (so it’s probably not sung to attract a mate).  Interestingly enough, whales don’t have working vocal cords so all the sounds they produce are probably made by moving air around inside their respiratory systems. If the singing whale is within 10 miles, divers and snorkelers can hear these songs. And if the whale is really close, the sounds actually reverberate through the hulls of our boats!

Is it possible to identify individual Humpbacks?
Yes.  In 1979, researchers off the Atlantic coast observed that each humpback has unique markings on the underside of its tail. Since humpbacks often lift their flukes prior to a long breath hold dive, it is possible to photograph and catalogue the sightings from the surface. Currently, over 5200 individuals have been identified in the North Atlantic, and more than 7000 in the North Pacific based on this technique.

What did the ancient Hawaiians think about the annual Humpback migration?
Although there is no Hawaiian word specifically describing the Humpback whale, the word “Koholä” means “whale”, and the Hawaiians certainly admired the power and grace of the whale, acknowledging their importance with place names throughout the islands. Hawaiians didn’t hunt whales (it is thought they didn’t like the taste of the meat) but only the ali’I (chiefs) were allowed to own the teeth from beached whales, weaving them into the revered and sacred lei niho palaoa.

Do humpbacks have natural predators?
In the cooler feeding grounds, Orcas have been observed attacking humpbacks. In the warmer breeding and calving grounds, it is thought that tiger sharks, hammerheads and pacific gray sharks will attack unprotected calves and older or sick whales. Humans still have major impact on the humpback population. Though the International Whaling Commission has protected the whales from commercial hunting since 1966, St Vincent and the Grenadines are permitted to kill 20 animals between 2013 and 2018 for consumption. The Danes in West Greenland are also allowed to hunt Humpbacks under the same Aboriginal Sustenance program…their quota is 10 Humpbacks per year between 2015 and 2018.

 

Sources:

Barlow, Jay. “Cetacean Abundance in Hawaiian Waters Estimated from a Summer/Fall Survey in 2002.” Marine Mammal Science, 22(2): 446–464 (April 2006). March, 2011.

http://www.nicholas.duke.edu/hawaii/readings/Mar%20Mammal%20Sci%202006%20Barlow.pdf

Hawaiian Islands Humpback Whale National Marine Sanctuary: March 2011.

http://hawaiihumpbackwhale.noaa.gov/

International Whaling Commission: Home and Catch Limits and Catch Taken: March, 2011.

http://www.nicholas.duke.edu/hawaii/readings/Mar%20Mammal%20Sci%202006%20Barlow.pdf

International Whaling Commission Catch Limits

https://iwc.int/catches#aborig

Kaufman, Gregory Dean and Paul Henry Forstell. Hawaii’s Humpback Whales: Island Heritage Publishing, 1986.

SPLASH:  March 2011.

http://cascadiaresearch.org/SPLASH/SPLASH-ExecutiveSummary.pdf

The Cultural Significance of Whales in Hawaii Brochure: March 2011.

http://hawaiihumpbackwhale.noaa.gov/documents/education.html

Tinker, Spencer Wilkie. Whales of the World: Bess Press Inc., 1988