Humpback Whale

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Humpback Whale (Monterey Bay collection)
Humpback Whale

Humpback whales are one of the most easily identifiable marine species in the world. An image of the giant beasts breaching nearly their entire length from the ocean or raising their tails with the huge, tattered-edged flukes is commonly seen both in conservation messaging as well as corporate logos and advertisements. Their scientific name translates to ‘big winged New Englander’ due to their large pectoral fins, which can reach 15 feet. Thousands of whalewatchers flock to boats that once hunted the animals for a chance to see one for themselves.


Content List

1. Scientific & Common Names

2. Characteristics

a. Breeding

b. Behavior

3. History

4. Present Status

5. References


Scientific & Common Names

Kingdom - Animalia

Phylum - Chordata

Class - Mammalia

Order – Cetacea

Suborder - Mysticeti

Family - Balaenopteridae

Genus – Megaptera

Species – novaeangliae

Common Names – humpback whale


Characteristics

The rorqual whales have well-known members, such as the humpback, blue, and fin, as well as the lesser known species sei, minke, and Bryde’s. Rorqual whales have folds running along their sides from the mouth towards their belly. These folds allow the whales – all of which are baleen whales – to open their mouths extremely wide while feeding. The baleen plates, which hang down from the top of their mouths, then filter out the plankton and small fish the animal consumes. They have dual blowholes at the top of their head, used for breathing. Humpbacks can measure up to 50 feet and 40 tones, with the females averaging slightly larger than males. They are dark grey or almost black on their dorsal (upper) side with a mottled transition to white on their ventral (under) side. The color pattern and shape of the flukes of the tail are unique to each animal and are used by researchers to identify the individuals.


Breeding

Humpbacks typically breed in the winter months and the gestation lasts about a year. The two and a half ton baby is born – twins are exceedingly rare – and will stay with the mother for a year, drinking up to 100 pounds of her nutritious milk a day, until they are weaned. Breeding occurs once every 1-3 years and the young mature at around 15 years. With a life expectancy of 45-50 years, a healthy female can produce many offspring, but the exact number is unknown.


Behavior

One of the best known humpback behaviors is singing, although the animals have no vocal cords and the way they produce the sound is still being studied. The performance is done by the males while they are suspended with their head down. The songs will vary from year to year and in different regions, but all males in an area will sing the same song, which can last for 20 minutes to over an hour and possibly be heard hundreds or even thousands of miles away. Some baleen whales will skim the water for food as they swim, but humpbacks feed by lunging at large concentrations of prey. Most fish will not swim through air bubbles, so the humpbacks will circle around below krill or fish and blow bubbles under them, corralling them, an activity that is often a cooperation between many members of a pod. Breaching and spyhopping are two activities that the whales are known for above the surface. They breach by rocketing towards the surface and then falling back in with a mighty splash. This may help to remove parasites from the animal or it may just be a social activity. Spyhopping is when they surface straight up until their flippers are exposed and survey the area. They can dive to 700 feet and remain submerged for 30 minutes. While those numbers seem impressive, the record holder is the Cuvier’s beaked whale with a submersion record of two hours and a depth of two miles, which is about 9000 feet deeper. However, humpbacks are listed in the Guinness World Records as having the longest migration of any mammal – 5095 miles.


History

The first aquatic ancestors of today’s whales – retaining their mostly useless hind legs - appeared 45-50 million years ago, but there is still much missing from the fossil record. They evolved from terrestrial hoofed animals and the closest relative on land is the hippopotamus. Vestigial pelvis and leg bones can still be found in modern whales. Until the 1960’s, the majority of the modern history of humpback whales involved hunting them, and most of the information we have comes from that industry.


Present status

While healthy adult humpback have no natural enemies, young or sickly animals can fall prey to orcas or some of the larger sharks species such as great whites or tiger sharks. Despite an international ban, the main predator of humpbacks remains humans. As many as 95% of all humpbacks were killed by whaling efforts in the twentieth century. Today, only a few countries still allow this practice. This species is distributed worldwide, with a current population between 15-40 thousand, and it is still red listed as endangered by the International Union for Conservation of Nature and Natural Resource (IUCN).


References

American Cetacean Society

The Cultural Lives of Whales and Dolphins by Hal Whitehead and Luke Rendell

Citizens of the Sea: Wondrous Creatures From the Census of Marine Life by Nancy Knowlton

The Whale: In Search of the Giants of the Sea by Philip Hoare

The Whales' Journey by Stephen Martin

Whale Odyssey: A Humpback Whale's First Perilous Year by Michael Bright

Guinness World Records