Humpback whale

The humpback whale (Megaptera novaeangliae) is a species of baleen whale. It is a rorqual and is the only species in the genus Megaptera. Adult humpback whales are very large, ranging from 14 to 17 metres (46 to 56 feet) long and can weigh up to 40 metric tons. They have a special body shape, with long pectoral fins and small bumps called tubercles on their heads.

Humpback whales are famous for jumping out of the water and other interesting actions at the surface, which makes them popular among whale watchers. Males make complex sounds or songs that can last from 4 to 33 minutes. These whales live in oceans and seas all around the world. They travel long distances between places where they eat near the poles and places where they have their babies near the equator. Their food is mostly krill and small fish, and they often use bubbles to help catch their food.

Humpback whales were once hunted a lot by people in the whaling industry, and their numbers dropped to around 5,000 by the 1960s. Today, their numbers have grown to about 135,000, but they still face dangers such as getting caught in fishing gear, hitting ships, and dealing with noise pollution.

Taxonomy

The humpback whale was first described in 1756 by a scientist named Mathurin Jacques Brisson, who called it baleine de la Nouvelle Angleterre. Later, other scientists gave it different names, but today it is known as Megaptera novaeangliae. The name comes from the shape of the whale's back when it dives.

Humpback whales are part of a group called rorquals, which also includes blue, fin, Bryde's, sei, and minke whales. They are known for their large front flippers. These whales have lived on Earth for millions of years and have spread to different parts of the world.

Characteristics

Adult humpback whales are usually about 14–15 m (46–49 ft) long, but some can reach up to 16–17 m (52–56 ft). Females are typically a bit longer than males. These whales can weigh as much as 40 metric tons (44 short tons). Calves are born around 4.3 m (14 ft) long and weigh about 680 kg (1,500 lb).

Humpback whales have a bulky body with a thin rostrum and long flippers. They have a short dorsal fin and special bumps called tubercles on their head and flippers. These tubercles may help them sense their surroundings. Their dorsal side is usually black, while the underside can be black or white. Each whale has unique color patterns and scars on their tail flukes, which help scientists tell them apart.

Behavior and ecology

Humpback whales often stay in small groups, but they sometimes come together in larger groups when feeding or when males are competing for females. They are active at the surface, doing things like jumping out of the water, slapping the water with their tails or flippers, and flipping their tails sideways. These actions might be for fun, to talk to each other, or to get rid of parasites.

These whales swim at a steady pace but can go faster if they feel threatened. They have long front fins that help them move well in any direction. Humpbacks like to rest at the surface and explore shallow areas. They can dive deep, sometimes for up to 20 minutes, and they may use these dives to talk to each other, find their way, or find food.

Feeding

Humpback whales eat from spring to fall. They enjoy eating krill, small fish, and other tiny sea creatures. They hunt using a clever method called bubble-net feeding, where they blow bubbles to trap their food. This helps them catch more food while using less energy.

Courtship and reproduction

Mating happens in the winter. Females can have multiple partners, and males often follow them closely, sometimes fighting for the chance to mate. After about 11 months of pregnancy, females give birth to one calf at a time. The young calves stay close to their mothers for about a year and can start eating adult food after six months. Humpbacks can live for more than 50 years.

Vocalizations

Male humpback whales sing complex songs, especially during the winter. These songs can last from a few minutes to several hours and have many different parts. Scientists think these songs might help in mating or bringing together groups of whales.

Predation

Sometimes, humpback whales face threats from other animals like orcas and great white sharks. When this happens, they can work together to protect their young and themselves. They use their strong flippers to defend against these predators.

Infestations and health threats

Humpback whales often have barnacles attached to their skin. These barnacles do not hurt the whales but can make it harder for them to swim. Whales can also get other small creatures that live on them or inside them. Sometimes, eating bad fish can make humpback whales sick.

Range

Humpback whales live in oceans all around the world, except in areas near the equator and in very cold northern waters. They are often found close to shorelines and like to gather in areas where the ocean is shallower near land. These whales spend their winters in warm waters near the equator and their summers in colder waters, even close to polar ice. They travel very long distances between these areas, sometimes up to 8,000 kilometers (5,000 miles) in one direction.

In the North Atlantic, there are two groups of humpback whales. One group spends its winters in the West Indies, from Cuba to northern Venezuela, and its summers near New England, eastern Canada, and western Greenland. The other group winters near the Cape Verde Islands and northwest Africa, and summers near Iceland and Norway. In the North Pacific, there are at least four groups, with some traveling between Mexico, Central America, the Hawaiian Islands, Okinawa, and the Philippines. There is also a special group that stays year-round in the northern Indian Ocean, mainly around Oman.

In the Southern Hemisphere, humpback whales are divided into seven groups. These groups travel between breeding areas near the equator and feeding areas in colder southern waters, including areas near Antarctica. Some groups are found near South America, Africa, Australia, and islands in the southern Pacific Ocean.

Human relations

Whaling

Main article: Whaling

See also: Whaling in Japan

Humpback whales have been hunted by people since the late 1500s. They were often the first kind of whale caught in new areas because they live close to shore. In the 20th century alone, around 28,000 were caught in the North Pacific and over 200,000 in the Southern Hemisphere. By 1946, when the International Whaling Commission was created to manage whaling, North Atlantic populations had fallen to just 700 whales. The IWC introduced rules and seasons for hunting and, in 1966, banned the commercial hunting of humpbacks to prevent them from disappearing completely. By that time, there were only about 5,000 left worldwide.

Today, only a few humpback whales may be caught each year near the island of Bequia in Saint Vincent and the Grenadines, and this does not seem to threaten the local group of whales. In 2010, the IWC allowed Greenland's local people to hunt a small number of humpbacks for three years.

Whale-watching

Main article: Whale watching

See also: Whale watching in Australia

Humpback whales are very popular for whale-watching trips because they are active near the surface and often get used to boats, making them easy to see. Whale-watching began in New England and Hawaii in 1975. In Hawaii, this activity helps the local economy earn about $20 million each year. While whale-watching can help people care more about protecting these animals, boats can sometimes stress the whales or interrupt their feeding, mating, and time with their young. Rules have been made to keep boats a safe distance from the whales.

Conservation status

The humpback whale is currently listed as not in danger by the IUCN Red List. There are about 135,000 humpback whales in the world, and their numbers are growing. In different parts of the world, there are roughly 13,000 in the North Atlantic, 21,000 in the North Pacific, and 80,000 in the southern hemisphere. However, the small group of humpback whales in the Arabian Sea, with only about 80 left, is considered at risk.

Even though many humpback whale groups have grown since the days when people hunted them, they still face dangers. These include getting caught in fishing nets, hitting ships, and noise from human activities. Scientists have studied how oil might affect whales and found that it does not stick to their special feeding structures and can be washed away easily.

Since 2016, more humpback whales have been found unable to continue swimming along the Atlantic coast of the US. This led experts to issue a warning about these events. The main reasons for these situations are collisions with ships and getting tangled in fishing gear. In the area around the Strait of Magellan, humpbacks are often reported in collisions with ships. To help prevent these collisions, ideas have been suggested to slow down ships near the Francisco Coloane Marine and Coastal Protected Area.