The Humpback whale is among the biggest and the most easily recognized of the whale species. They are distinguished from other whales because of their large flippers, which are almost one-third the length of their body, and a hump on their backs. Their color ranges from gray to black, with white markings on their belly. These markings can be compared to fingerprints, different for every whale, and they allow researchers to identify individuals.
Humpback whales inhabit all major oceans from sub-polar latitudes to the equator. There are four global populations of Humpbacks and they do not interact with each other: North Pacific, Atlantic, Southern Ocean, and Indian Ocean populations. Humpbacks live at the ocean's surface, both in shallow coastline waters and the open ocean. They migrate seasonally from the warm tropical waters where breeding and calving takes place, to feeding areas in Arctic waters.
Typically, Humpback whales live alone or in small loose groups that can disband after a few hours. Groups may stay together longer in summer to forage and feed cooperatively. Longer-term relationships between pairs or small groups, lasting months or even years, have rarely been observed. Humpbacks sing more loudly than most other whales. Its songs can be heard over distances of several miles. The songs are sung by adult males, last up to 20 minutes, and then are repeated. Every year all the male whales sing the same song. While a whale sings, it floats in the water, its head down, and it is relatively motionless. Whale’s song purpose is not clear, though it may have a role in mating. Humpbacks make long journeys. During migration they travel slowly, socializing and resting along the way. Each humpback population has its own migratory route. They usually spend winter in warm, low latitude or tropical waters mating and giving birth, and during the rest of the year, they feed in cooler, higher latitude polar waters.
Humpbacks are polygynous, and the males compete aggressively for mating access to females. They breed during winter in tropical waters. After a gestation of 11.5 months, one calf is born. Females must feed their calves around 45 kg of milk every day for 5-7 months until weaning, and calves may remain with their mothers for as much as a year. Mothers are affectionate and protective towards their calves, swimming nearby and often touching their babies with their flippers. Male humpbacks do not give parental support for calves. Mating usually takes place once every two years, though sometimes it occurs twice within three years. These whales are reproductively mature when they are 4-5 years old, and the birthing interval is 2 years.
Humpbacks are vulnerable to changes in the marine environment and also are threatened by water and noise pollution and the potential changes to fish stocks due to climate change. They may be harmed by collisions with ships, overfishing, and getting tangled in fishing gear. Offshore gas and oil development is also a threat to this species.
According to the IUCN Red List, the total Humpback whale population size is around 60,000 animals, including estimates for specific populations: North Atlantic - around 10,752 animals; North Pacific - 18,302 animals and 36,600 whales in the southern hemisphere. The number of humpback whales is increasing today and this species is classified as Least Concern (LC).