Critter of the Month April 2019

Humpback Whale breaching ocean surfaceCommon name:

Humpback whale

Critter contributor:

Scott Moore, Flickr

Humpback whales, like all rorquals, are long and slender whales that are much more streamlined than other large whales. They have a pointed snout, paired blowholes and a broad flat rostrum. They have throat grooves, which help to streamlining their shape and also allows their throat area (called the cavum ventrale) to expand during feeding. Their baleen plates are broad and short, and their dorsal fin is curved.

The humpback whale’s scientific name means “giant wings.” This refers to their large pectoral fins which are about one-third of the animal’s entire body length. These animals are best known for their complex whale songs. It is only the males who perform these hauntingly beautiful vocalizations. They have a rich repertoire that covers many octaves and includes frequencies beyond the threshold of human hearing. When a whale is singing, it floats suspended in the water, head down and relatively motionless. Dominance, aggression, and mate attraction are all behavior that may be related to singing. Researchers have discovered that whales in the same geographic area sing in similar “dialects.” Whale song patterns change gradually over time, so new songs emerge every few years.

Globally, humpback whale populations were depleted by the commercial whaling industry at the beginning of the 20th century. In 1973, however, the United States government made it illegal to hunt, harm or disturb humpback whales. When the Endangered Species Act was passed in 1973, the humpback whale became listed as endangered. Additional laws protect humpback whales, such as the Marine Mammal Protection Act, various state wildlife laws and the National Marine Sanctuaries Act. Their protection is also extended as a resource of national significance within the Hawaiian Islands Humpback Whale National Marine Sanctuary. In 1993 it was estimated that there were 6,000 whales in the North Pacific Ocean. Through the various protections made, the North Pacific humpback whale population now numbers more than 21,000. This is a true conservation success story. Protection of important ecological habitats are necessary for the long-term recovery of all humpback whale populations.