North Atlantic Right Whale

The North Atlantic right whale is a right whale species. These are baleen whales, which means they have baleen plates instead of teeth. Similar to other species in its genus, this whale is also known as the black whale or northern right whale. They get the ‘right’ in their name because whalers considered this whale the right one to hunt, with its slow movement and tendency to float on the water’s surface after being killed.

A group of right whales is called gam, herd, mod, pod, or school.

Description

Size: Length: 660 inches (55 ft.)

Weight: 140,000 lbs (63502 kg)

Body and Coloration: This animal is black with a heavyset body, a broad tail with deep notches, and a smooth trailing edge. White patches called callosities, cover their black heads and bellies. These callosities are different for each whale. These whales do not have dorsal fins; their broad pectoral fins are relatively short and shaped like paddles. Females are usually larger than males.

The males have the largest testicles among the whole animal kingdom, weighing almost a ton (900 kg), making up 2% of their body weight.

Range and Distribution

The distribution of North Atlantic right whales is throughout the western North Atlantic ranging from Florida in the United States to Nova Scotia in Canada. During migration, some might even travel as far as Denmark, the Davis Straits, the Gulf of St Lawrence, Iceland, and Norway.

Their distribution and migratory patterns have changed over the years as a result of their prey changing locations due to climate change.

Habitat

These mammals inhabit sub-polar andtemperate waters. Their preferred territories depend on the type of hemisphere they live in and the time of the year. They spend most of their time near bays, peninsulas, and shallow coastal waters, providing them with food abundance, security, and shelter. The Browns-Baccaro Bank, the Bay of Fundy, the Great South Channel, and the Cape Cod Bay are critical habitats for these whales, marked by dense copepod populations. 

They migrate between calving grounds in the south of the range, where the water is warmer, to feeding grounds in the north of the range.

Diet

Their primary diet consists of zooplankton and krill, with the preferred type being large copepods.

Behavior

• This whale socializes in groups at the surface of the ocean. They often breach while slapping their fins and tails on the surface.
• They usually travel solo and sometimes in a small group containing 2-12 whales.
• While threatened by predators, they may form a defensive circle swarming together temporarily with their tails flailing outwards.
• These whales make different noises like bellowing, grunting, moaning, mooing, and sighing.
• Similar to other baleen, right whales capture their prey using filter feeding.
• Sometimes females swim on their backs with newborn calves cradling on their bellies.

Lifespan

The lifespan of this animal extends up to 70 years, with the average being 45 years for females and 65 years for males.

Adaptations

• Its thick blubber regulates the whale’s body temperature, which helps it to stay warm in cold waters.

Mating and Reproduction

Being polyandrous, they do not form any permanent pair bonds. There is no aggression between males during courting, which is rare behavior among mammals. The breeding season lasts from December to March. After mating, they go their separate ways.

A single calf is born after 12-13 months of gestation. Right whales give birth to one calf at an interval of three to four years. At birth, each calf is about 168 inches (14 ft.). The newborn stays close to their mother until they wean around one year. During the first year, they learn about the critical feeding ground from their mother. They reach their reproductive maturity around 8-11 years old.

Predators

Due to their intimidating size, most predators do not approach them; however, killer whales and sharks might target the calves.

Conservation Status

According to the IUCN, the North Atlantic right whale is “Critically Endangered” or “CR”.

During the 19th century, commercial whalers hunted these whales to near extinction. Their survival is threatened by entanglement in fishing nets, separation from calving areas due to shipping traffic, and ship collisions.

The current estimated population of this species is fewer than 350, with 200-250 adults and a below-average number of new calves.

Interesting Facts

• They maintain the ocean food chain. Their excrement helps in stimulating phytoplankton growth, which provides a clean breathing atmosphere for all animals by pulling out all the carbons.
• Researchers use their ear wax to determine their age after death.
• The scientific name of North Atlantic right whales translates to “good or true, whale of ice”.