Humpback Whale Fact Sheet
By Julia Illar
The humpback whale, also known by its scientific name of Megaptera novaeangliae, is a large cetacean best known for its vocalizations and complex song used for mating. The humpback spends time in Alaska during the spring, summer, and fall. They also may be seen in the waters off of Japan, Mexico, and Hawaii in the winter months. Humpbacks have one of the longest migration patterns of any animal on the planet.
Humpbacks are called “humpbacks” because of the hump on their back that you can see when they dive. As they fluke, this feature becomes very apparent. This large cetacean ranges in size from 40 to 50 feet and weighs in around 40 tons, which is the equivalent to almost 4 school buses! They appear to have knobby heads, and each whale has a unique pattern on the undersides of their tailfin (or “fluke”).
Humpback whales can have elaborate displays, making the a popular whale to watch. Whale watching in the state of Alaska supports around 850 jobs annually and about $23.4 million in labor income.
Current threats to the humpback whale include:
Vessel Strikes
Climate Change
Entanglement in Fishing Gear
Vessel-Based Harassment
DID YOU KNOW…
The humpback was hunted commercially up until the 1980’s, and prior to this its population was reduced by nearly 95%.
• Humpbacks feed off of krill and small fish. Using their baleen plates as a sieve, they filter water through the baleen all while keeping the fish in their mouths.
• Females produce a calf every 2 to 3 years and gestation lasts 11 months.
• Calves are not thought to form long-term associations with their mothers, but they are often found in the same breeding and feeding areas as them.
Photo courtesy of NOAA Fisheries
SCIENTIFIC AND COMMON NAMES
Megaptera novaeangliae; Humpback whale; Big Wing of New England.
GENERAL DESCRIPTION
The humpback whale is a “baleen” whale known for its long and narrow flippers that are ⅓ the length of their bodies and are scalloped along the edges. Modern wind turbines were created with three-dimensional bumps on their leading edges inspired by these whales’ fins. This innovation improved aerodynamic performance and even made for quieter operation. Humpbacks have such long, narrow flippers because they aid in maneuverability. They also allow these whales to roll around and move in circular patterns.
Baleen are flexible plates that act as a filter feeding system inside a humpback whale’s mouth. Humpbacks are able to use the row of baleen to push water out of their mouth while keeping krill and other food items inside. This allows them to not swallow excessive seawater.
Humpbacks have a black and gray upper surface, and their bellies are mostly white in color. The coloring of these whales is to help avoid predator interactions. The white belly looks like the light color of the sky which provides camouflage from predators that swim below and look upwards. Their coloring also provides camouflage from the surface, because their dark upper half blends in with the ocean water when viewed from above. The knobby bumps on their heads are known as “tubercles” and are the size of a fist. They contain one hair follicle each and attach to a system of sensitive nerves.
Humpback whale flukes can extend up to 18 feet wide and are serrated along the edge. Each whale has a distinguished pattern on the underside of its flukes that is described as its fingerprint. When using photographs to identify whales (photo ID), the fluke prints of humpback whales can be used to identify individuals. Captured images can be compared to other pictures and cataloged for future identification.
Photo courtesy of NOAA Fisheries
Get up close to a humpback in Juneau, Alaska…
RANGE
Map courtesy of NOAA Fisheries
The humpback whale lives and migrates throughout many of the world’s oceans. In Alaska, humpback whales travel through Kachemak Bay, Prince William Sound, Southeast Alaska, and throughout most of the waters surrounding the state. They can also be found along the East Coast of the United States and in waters along Canada, Hawaii, Japan, Central America, and Mexico. These whales travel throughout most of the world’s oceans aside from polar regions.
While females calve, they prefer shallow and warm waters near coastal shores or offshore reef systems. When not calving, humpbacks can be found following their food sources. Their prey are often found in cold, nutritionally-productive waters.
Humpback whales are known to seasonally migrate and can sometimes travel 5,000 miles from their summer feeding grounds to their tropical calving areas. In some cases, humpbacks migrating from Alaska to Hawaii have completed the 3,000-mile trip in nearly 28 days!
Watch a video of migrating Humpback whales making their way from cold Antarctic waters to warmer Australia waters…
Threats/Concerns
Humpback whales are no longer hunted in the U.S. and are protected under the Endangered Species Act and the Marine Mammal Protection Act. They also have now been protected worldwide from commercial whaling with the exception of some select countries. Humpbacks used to be whaled regularly for oil and baleen. They now face threats like entanglement in fishing gear, vessel strikes, harassment from boats, and ocean noise or sound pollution.
Vessel strikes are common in areas where humpbacks are in coastal regions with heavy ship traffic. Entanglement can be caused by many types of gear, such as moorings, gillnets, pots, and traps. These items can remain on the whale and cause fatigue, severe injury, and compromised movement.
Boater harassment can stress and confuse humpbacks trying to feed or migrate. Because they are active whales, they are popular for whale watching and other tourist attractions. Viewing guidelines are in place in many countries and states in an attempt to prevent boater harassment.
LIFE HISTORY
Humpbacks reach sexual maturity between 4 and 10 years of age. Females tend to have a calf every 2 to 3 years after reaching sexual maturity and mating. Gestation lasts around 11 months and calves are born 13 to 16 feet long.
Calves are born in warm, tropical waters. Mothers migrate during the winter to warm waters to calve and/or mate. Soon afterwards, mothers and their calves make their way to more nutrient-rich waters (typically colder ones in lower latitudes), during the summer months. Calves will nurse from their mothers for about a year before being weaned. It is not believed that there are long term mother and calf associations, but they are often found in the same feeding and breeding areas as one another. During the nursing stage, mothers are protective of their young.
Humpback whales are known for their large range of noises as well as squeaks, squeals, and grunts. Only male humpback whales sing, similar to how male songbirds sing. It is believed that this observation in humpback whales is a mating behavior to attract a female, although much of this behavior is still being studied. There are many theories as to what this singing behavior could mean. Some theories include the idea that the song functions as an index of association between males. This could help individuals to determine their cooperativeness and if they are competing for females. The song is unique and extremely complex.
Humpback whales are also known for their active breaching and surface behaviors and are known to be social cetaceans. “Breaching” is when a whale propels itself up and out of the water, with more than half of its body leaving the ocean. Again, there are many theories as to why humpbacks are engaging in this behavior. Some theories as to why this occurs include: communication to other whales, dislodging of barnacles, or even just out of enjoyment. They could also be sloughing off dead skin, or it could be a behavior to deter predators like killer whales. It is also thought that behaviors like “tail lobbing” (where a humpback smacks its flukes against the surface of the water) could be to stun prey or to scare off predators. “Pec slapping” is where humpback whales take their large pectoral fins and slap them against the surface of the water. The purpose of this behavior also has many theories, but some include using it as a means of communication with others as well as a way to stun prey.
Photo courtesy of Whale SENSE
Check out this video of a humpback and her calf…
DIET
Humpback whales eat a diet rich in small crustaceans. This consists of mostly krill, which are small shrimp-like crustaceans. They also feed on small fish and are known to even eat squid.
Humpbacks are known as having diverse diets and tend to follow the food source in lower latitudes. They use many techniques to hunt their prey. These consist of methods like using “bubble nets” or slapping the water using their pectoral fins to stun prey. Bubble-net feeding is where humpbacks will swim below their prey and expel small amounts of air through their blowholes. This creates a curtain of rising bubbles that travels upwards through the water and condenses their prey by pushing them towards the surface of the water. From there, the whales lunge upward and use their baleen to filter out water while swallowing the trapped fish.
Watch a humpback use bubble-net feeding to capture prey!
CULTURAL SIGNIFICANCE
Humpback whales were originally hunted by some indigenous groups in Alaska. Namely, the Aleut culture would use a two-person kayak, also called a “umiak”, and a harpoon to hunt humpbacks. Baleen was sometimes used for holding waterfowl snares open, and whale bone was used to split wood. As there were increasing concerns with whaling and the decrease of the humpback population, hunting and consumption of the whale dwindled.
HUMPBACK COLORING SHEET
We hope you learned something new about the humpback whale! Check out our Facebook, Instagram, and Twitter to learn more about Alaska’s wildlife, and subscribe to our free newsletter to get updates from the Alaska Wildlife Alliance! If you want to support wildlife conservation in Alaska, you can become a member for only $35 dollars a year!
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Information obtained from: Britannica, Alaska Department of Fish and Game, NOAA Fisheries (x2), Traditional Animal Foods, Pacific Whale Foundation, IPWatchdog, Whales Online, Whale Trust, and Whale SENSE.
