Humpback Whale

Humpback Whale

Tim Hauf, timhaufphotography.com

Scientific Name
Megaptera novaeangliae

Introduction
The spectacular humpback whale, that performs acrobatic leaps, is common within the Channel Islands National Park and Channel Islands National Marine Sanctuary boundaries. Generally, the humpback whale can be seen from mid-May to mid-September on whale watching boats servicing the public in the vicinity.

Quick and Cool Facts

• Humpback whales produce the most diverse range of sounds known for any whale and some of the longest and most varied sounds of any animal in the world. ⁴
• The estimated population on the United States west coast is estimated at about 597 individuals. (2010 review by Channel Islands National Marine Sanctuary).⁴
• Some humpback whales make a round trip journey of 10,000 miles.⁴
• The humpback whale gets its name from fact that the dorsal fin sits on a large "hump" on the back, which is noticeable when the whale arches its back and dives.4
• They are also seen swimming on their backs with both flippers in the air. ⁴
• Humpback whales are slow swimmers compared to other whales. They can reach up to 16 miles per hour, but average only 2-9 miles per hour.⁴

Appearance
As described by the "FAO Species Identification Guide: Marine Mammals of the World", the the humpback whales flippers are extremely long (up to one-third of the body length) with a series of bumps, including 2 more prominent ones in consistent positions on the leading edge, more-or-less dividing the margin into thirds. The flukes have a concave, serrated trailing edge, and the dorsal fin is low and broad based (usually sitting on a hump). The head has a single median ridge, and the anterior portion of the head is covered with many bumps (each containing a single sensory hair). The body is black or dark grey dorsally and may be white ventrally, but the borderline between dark and light is highly variable and seems to differ by population. The flippers are white on the ventral side and vary from all-white to mostly black on the dorsal surface. The ventral side of the flukes also varies from all-black to all-white. There are 270 to 400 black to olive baleen plates, and 14 to 35 ventral pleats extending back to the navel or beyond. The blow is rather low and bushy for a balaenopterid, reaching only 3 m. It may sometimes appear V-shaped. At close range, the humpback is one of the easiest whales to identify. At a distance, however, there can be some confusion with other large whales, especially blue and sperm whales. When a closer look is obtained, humpbacks are generally unmistakable. As far as size, the adult humpback whales are 45 to 56 in length, with females being about 6 feet longer than males on the average.Newborn calves are 16 to 18 feet in length and weigh up to one ton. Weights of at least 35 tons or 70, 000 pounds are attained by adults. Individual humpback whales can be identified using photographs of the distinctive markings on the undersides of their flukes.²
 

Range
Humpbacks are widely distributed in all oceans, ranging from tropical wintering grounds near islands and continental coasts to open-ocean temperate and sub-polar summering habitats.⁵

Habitat
Humpbacks feed and breed in coastal waters, often near human population centers, and this helps make them one of the most familiar of the large whales. They migrate from tropics (breeding areas) to polar or sub-polar regions, reaching the ice edges in both hemispheres (feeding areas);their migrations take them through oceanic zones.

Feeding
According to NOAA Fisheries, the humpback whale has a unique way of feeding by using a technique of lunging through patches of krill (small shrimplike crustaceans) or fish and then gulping vast mouthfuls of water. Humpbacks also use an impressive skill called "bubble-netting" which involves swimming in a spiral beneath their prey and blowing out air from their blowholes. This "net" of bubbles surrounds the shoal of fish or krill, then, the humpback swims through the center with its mouth open. These techniques are the most diverse, as well as spectacular of all baleen whales.^3,5

Reproduction
Humpback whales are probably old enough to mate at about 7 years of age.Females are pregnant for about 11 to 12 months and get pregnant approximately every two to four years. Calves are born on wintering grounds in tropical and subtropical regions and are able to swim and can grow 1.5 feet (0.5 meters) per month while nursing.Females nurse their new born calves in warm, shallow water.

Humpbacks have very complicated courtship behaviors and many male humpbacks can surround a female and compete with each other to get close to the female.Sometimes the competition involves males lunging at and bashing into each other. Males also appear to compete for access to estrus females, by using their now well-known complex songs as part of their breeding display. At the end of the mating and calving season, humpback whales migrate to cold, productive waters to feed.⁵

Conservation Status
Humpback whales were not a favorite target of Yankee whalers. However, because of their relatively slow swimming speeds and coastal habits, they were an early target of modern large-scale commercial whaling, beginning with shore based whaling in many areas. Commercial whalers hunted humpbacks into the 20th century, reducing the number of the species to possibly 10 percent of the original population worldwide.

Humpback whales are now protected by the Endangered Species Act and the Marine Mammal Protection Act, making it illegal to harass or kill a humpback whale in United States' waters. In addition, the International Whale Commission gave humpback whales worldwide protection status in 1966. Since then it has been illegal to hunt humpback whales anywhere in the world. Steps are also being taken to try to reduce ship collisions and fishing gear entanglement.

In August 2008, the IUCN, International Union for Conservation of Nature, changed humpback's status from Vulnerable to Least Concern, although two subpopulations remain endangered. The United States, through a review conducted by the U.S. National Marine Fisheries Service, is considering listing separate humpback populations, so smaller groups, such as North Pacific humpbacks, which are estimated to number 18,000-20,000 animals, might be delisted. This is made difficult by humpback's extraordinary migrations, which can extend the 5,157 miles from Antarctica to Costa Rica.^1,4,6

References and Additional Information

1. http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/humpbackwhale.htm
2. FAO Species Identification Guide: Marine Mammals of the World, Jefferson, T.A., S. Leatherwood, and M.A. Webber, 1993.
3. Channel Islands National Marine Sanctuary: http://www8.nos.noaa.gov/onms/Park/Parks/SpeciesCard.aspx?refID=1&CreatureID=20&pID=3
4. NOAA's National Marine Fisheries Service, Office of Protected Resources, The Kids' Times: Volume II, Issue 5, Humpback Whale
5. http://www.afsc.noaa.gov/nmml/education/cetaceans/humpback.php
6. http://www.iucnredlist.org/details/13006/0