Humpback Whale

Humpback whales (Megaptera novaeangliae) are baleen whale species. It is one of the bigger rorqual species, with adults measuring 12–16 meters (39–52 feet) in length and weighing 25–30 tons. With lengthy pectoral fins and a knobbly skull, the humpback has a characteristic body form. 

About Humpback Whale

It is well-known for breaching and other unique surface activities, making it a favourite whale-watching destination. Males sing a complicated melody that lasts 10 to 20 minutes and is repeated for hours. Each season, all the male whales in a group will sing the same song, which will be different. Its function is unknown, however, it may aid in the induction of estrus in females. 

Humpback whales are found in oceans and seas all around the world, and they move up to 25,000 kilometres (16,000 miles) per year. They eat in polar waters and then travel to tropical or subtropical seas to mate and give birth, fasting and surviving on fat stores. Krill and tiny fish make up the majority of their food. The bubble net technique is one of the several feeding strategies used by humpback whales. 

The humpback whale, like other big whales, was a target for the whaling business. Before a 1966 moratorium, the species was hunted to extinction, with its population dropping by an estimated 90%. While populations have largely recovered to around 80,000 individuals globally, the species continues to be harmed by entanglement in fishing gear, ship crashes, and noise pollution. The blue, fin, Bryde's, sei, and minke whales are all members of the Balaenopteridae family, which also contains humpback whales. The rorquals are thought to have split from the rest of the Mysticeti suborder as early as the middle Miocene age. When the members of these families split from one another, however, is unknown. The humpback is the only member of its genus, although being closely related to the enormous whales of the genus Balaenoptera. Recent DNA sequencing has revealed that the humpback whale is more closely linked to some rorquals, like the fin whale (B. physalus) and probably the grey whale (Eschrichtius robustus), than to others like the minke.

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Mathurin Jacques Brisson named the humpback as baleine de la Nouvelle Angleterre in his Regnum Animale of 1756. Georg Heinrich Borowski described the species in 1781, using the Latin version of Brisson's name, Balaena novaeangliae. Lacépède renamed the humpback B. jubartes in 1804, removing it from the Balaenidae family. The humpback was classified as Megaptera longipinna by John Edward Gray in 1846, but Remington Kellogg returned the species names to Borowski's novaeangliae in 1932. The common name comes from the way their backs curve when they dive. Megaptera gets its name from the Ancient Greek words mega- ("giant") and ptera/ ("wing"). It alludes to their huge front flippers. The term "New Englander" was most likely given by Brisson in response to frequent sightings of humpback whales off the coast of New England. The British Antarctic Survey established in mid-2014 that the various populations in the North Atlantic, North Pacific, and Southern Oceans are more different than previously assumed through genetic study. Some scientists argue that these two groups should be considered distinct subspecies that are developing separately.

Anatomy

Humpback whales are distinguished by their stocky bodies, prominent hump, black dorsal colouration, and extended pectoral fins. Tubercles, which are hair follicles, cover the head and lower jaw and are a distinguishing feature of the species. The fluked tail has wavy trailing edges and rises above the surface when diving. On either side of their lips, humpbacks have 270 to 400 darkly pigmented baleen plates. The plates are 18 in (46 cm) wide in the front and around 3 ft (0.91 m) wide behind the hinge in the back.

Ventral grooves stretch halfway along the bottom of the body, from the lower jaw to the umbilicus. These grooves are smaller (typically 14–22) than those found in other rorquals, but they are somewhat broad. In the female's vaginal area, she possesses a hemispherical lobe that is around 15 cm (5.9 in) in diameter. Males and females can be distinguished visually by this. In most cases, the male's penis is hidden in the genital slit.

Humpback Whale Size

The average size of a humpback whale in the case of males reaches a height of 13–14 m (43–46 ft) when fully grown. Females are slightly bigger, measuring 15–16 m (49–52 ft); one huge specimen was 19 m (62 ft) in length and had 6 m (20 ft) pectoral fins. According to whaling records, the largest humpback whale size on record was a female killed in the Caribbean; she was 27 meters (89 feet) long and weighed 90 metric tons (99 short tons), however, the veracity of such exceptional statistics is hard to check. The biggest whales measured by the Discovery Committee scientists were a female and a male at 14.9 and 14.75 meters (48.9 and 48.4 feet), respectively, from a sample size of only 63 whales. The average body mass is 25–30 metric tons (28–33 short tons), with big specimens weighing more than 40 metric tons (44 short tons).

Fins

The long black and white tail fin might reach a third of the length of the body. Several theories have been proposed to explain the pectoral fins of the humpback whale, which are proportionately the longest fins of any cetacean. Long fins' enhanced agility, as well as the greater surface area's use for temperature management while migrating between warm and cold climes, may have aided this adaptation. In battles with killer whales, these extraordinarily long, heavy pectoral fins with a row of knuckle-like bumps along their front margins are excellent weapons. Coronula diadema, a big, sharp-cornered barnacle, frequently clings there, providing a natural analogue of knuckledusters. Humpback whales have been seen defending a grey whale calf that had recently been slaughtered by killer whales against predators.

Identifying Individuals

Individual animals may be distinguished by the different patterns on their tail flukes. The quantity of white vs. black on the fluke, as well as scars, are used to identify it. After that, the humpback whales are assigned a catalogue number.

Researchers used data on whales in the North Atlantic from 1973 to 1998 to create a study that provided extensive information on gestation dates, growth rates, and calving periods, as well as enabling for more accurate population estimates by emulating the mark-release-recapture methodology. During this time, the College of the Atlantic created a photographic inventory of all known North Atlantic whales, which is still in use today.

Behaviour

Following migration toward the equator from summer feeding sites closer to the poles, courtship rituals take place throughout the winter months. In most cases, competition is severe. Escorts, or unrelated males, commonly track females and cow-calf couples. Males from competitive groups around a female in order to compete for the privilege to mate with her. As failed guys go and others join, the group size fluctuates. Breaching, spy hopping, lob-tailing, tail-slapping, pectoral fin-slapping, peduncle tosses, charging, and parrying are examples of behaviours. Whalesong is assumed to play a crucial role in triggering estrus in females and in mate selection, but it may also be utilized to establish dominance amongst males. Female humpback whales are polyandrous, meaning they have several male mates throughout their lives.

Females usually have babies every two to three years. The pregnancy lasts 11.5 months. The Northern Hemisphere's top months for birth are January and February, whereas the Southern Hemisphere's high months are July and August. Females do not reproduce again for one to two years. A recent mitochondrial DNA study suggests that populations living close together may reflect different breeding pools. Humpback whale newborns have only been seen a few times. A four-minute birth was seen off the coast of Madagascar. Hybridization between humpback whales and other rorquals has been seen.

Interactions Among the Species

Humpback whales are a sociable species that socialize with other cetaceans like bottlenose dolphins. Humpback whales interact with the right whales. These behaviours have been seen in all of the world's seas. Off the shores of Mozambique and Brazil, records of humpback and southern right whales displaying what was described as mating activities have been observed. Other species such as blue, fin, minke, grey, and sperm whales are seen in mixed groups alongside humpback whales. Gray, fin, and right whales have all been spotted interacting. In 2014, researchers saw a male humpback whale singing an unknown song and approaching a fin whale off the coast of Rarotonga. Nan Hauser, a snorkeler and whale researcher, claimed in September 2017 at Rarotonga, Cook Islands, that two adult humpback whales had shielded her from a 4.5 m (15 ft) tiger shark, with one whale pushing her away from the shark and the other using its tail to block the shark's advances.

Range and Habitat

Humpback whales may be found in all major seas, with a vast range of habitats stretching from the Antarctic ice border to 81°N latitude. North Pacific, Atlantic, Southern Ocean, and Indian Ocean populations are the four worldwide populations. These are two different populations. Although the species has a worldwide range and is rarely thought to cross the equator line, seasonal studies in Cape Verde imply that populations from both hemispheres may interact. Aside from the Arabian Sea group, year-round presences in British and Norwegian seas have been documented. Parts of the world's wintering grounds, including the Pitcairn Islands, Northern Mariana Islands (e.g., the Marpi and CK Reefs near Saipan), Volcano Islands, Pasaleng Bay, Trindade and Martin Vaz, Mauritius, and Aldabra, have been poorly researched or unreported. Whales were historically scarce in the Mediterranean and Baltic Seas, but as world populations have rebounded, their numbers have grown in both. More whales may move into the inland sea in the future, not just for wintering but also for feeding, based on recent increases in the Mediterranean basin, including re-sightings. 

Humpback whales are also re-entering previous ranges, including Scotland, Skagerrak, and Kattegat, as well as Scandinavian fjords like Kvnangen, where they had not been seen in decades. Feeding regions in the North Atlantic span from Scandinavia to New England. In the Caribbean and Cape Verde, breeding takes place. Whales may reproduce in the South Atlantic and Indian Oceans, as well as along the shores of Central, Southern, and Southeast Africa (including Madagascar). Whale trips to the Gulf of Mexico are rare, though they have occurred in the past. Around 10% of the world's population of the species may migrate to the Gulf of Guinea in the South Atlantic. The songs from Cape Lopez and the Abrolhos Archipelago show that there are trans-Atlantic mixings of western and southeastern populations. Every winter, a massive population expands over Hawai, from the island of Hawaii to Kure Atoll in the north. These creatures may be found from the California coast to the Bering Sea. Humpback whales were first seen in Hawaiian seas in the mid-nineteenth century, and they may have displaced North Pacific right whales, which were killed to near-extinction.

In Asia

Whales were found in locations in the Batanes, Sulu, and Celebes Seas, including off Palawan, Luzon, Malaysia, and Mindanao, with larger numbers at today's Cape Eluanbi and Kenting National Park, suggesting that historical wintering distributions were considerably wider and more southerly dispersed. Whales were sighted in regions throughout the Batanes, Sulu, and Celebes Seas, including off Palawan, Luzon, Malaysia, and Mindanao, with larger populations at today's Cape Eluanbi and Kenting National Park. In recent years, unconfirmed sightings have been reported around Borneo. The earliest sightings in contemporary Taiwan were in 1994 off the coast of Hualien, followed by a successful escape from entanglement off the coast of Taitung in 1999, and continued sightings around Orchid Island in 2000. Few (if any) birds migrate into Kenting National Park on a regular basis. 

Furthermore, despite practically yearly sightings along the coasts of Green and Orchid Islands, a very brief stay in these waters implies recoveries, as winter feeding has not taken place. Sightings have been reported along Taiwan's east coast, including a cow-calf pair. In 2009 and 2016, there were two reported sightings around Hong Kong. In Changhai County in October of 2015, a group of three or four individuals, including a cow/calf pair, was one of the first recorded sightings within the Yellow Sea. Whales have been gathering at Hachij-jima since November 2015, well north of the usual breeding sites in the Bonin Islands. As of January 2016, all breeding activity had been confirmed, with the exception of giving birth. As a result, Hachijo-jima is the world's northernmost breeding habitat, located north of Amamishima, Midway Island, and Bermuda.

Let us take a look at a few humpback whale facts.

Humpback Whale Facts

According to the NOAA, humpback whales may grow to be 60 feet (18 meters) long and weigh up to 40 tons (about half the size of a blue whale). Their flippers may grow to be as long as 16 feet (5 meters), making them the world's longest appendage. Their tails are similarly enormous, reaching up to 18 feet (5.5 meters) in length. Females, like most whales, are bigger than males. Baleen whales, such as humpback whales, are baleen whales. Instead of humpback whale teeth, they have baleen plates, which are 270 to 400 fringed overlapping plates that dangle down from either side of the upper jaw. The plates are constructed of keratin, the same material that makes up human hair and nails.

The skulls of humpback whales are large and rounded, with bumps known as tubercles. According to the American Cetacean Society, each knob has at least one stiff hair (ACS). The role of the hairs is unknown, though they are assumed to be motion detectors.