Blue Zoo: Humpback Whales
Humpback whales, scientifically known as Megaptera novaeangliae, are found in all of the world’s oceans and can grow up to 15 meters long and weigh 30 tonnes (that’s about 50 feet and 6,600 pounds). The species belongs to a group called rorquals. The largest whales are almost all rorquals, including ones even bigger than the humpback (such as the blue whale, the largest species to ever roam the earth).
You might think an animal so big needs to eat large prey - but humpback whales don’t even have teeth! Instead of teeth, its mouth is full of baleen, just like other rorquals. Baleen is made of keratin, the same material as your hair and nails. The whale uses it to feed on very tiny prey animals, such as krill or herring. The baleen acts like a filter. The humpback takes a huge mouthful of seawater, then it squeezes the water out, while all the edible things are stuck inside.
Humpbacks are known to feed cooperatively as part of a groups. They swim in a circular formation below a school of fish. By strategically releasing bubbles from their blowholes, the team of humpbacks creates a “bubble net.” The fish see it as a barrier so they don’t swim through, and they become trapped. Then, the whales lunge into the circle with their mouths wide open, efficiently capturing their meal. You can see how it works in this video:
The whales don’t get to feed year round. Instead they migrate between cold polar waters where there is lots of food, and warm tropical waters where they can mate and give birth. The amazing migrations are the longest made by any mammal! Check out our infographic here to see where they travel.
During the mating season, male whales may spend hours “singing” a song, which to human ears sounds sad and melancholy. All the males in a group sing the same song, and each year that song changes. We explain this further in another post here. For a male humpback to successfully mate, he must compete with other males in an intense “heat run” which we describe here.
Humpback whales were one of the earliest targets of whalers and commercial whaling decimated their populations around the world by the mid-1900s. Thankfully, they were protected internationally from commercial whaling since 1966 – and this has paid off, big time. Initially the humpback whale had to be listed on the IUCN Red List as an Endangered species. By 1990, the status was reduced to Vulnerable. The size of the population has continued to increase and today the humpback whale’s conservation status is Least Concern.
The whales still face dangers along their migration: debris can choke or entangle them, overfishing can threaten the prey they eat, and increasing boat traffic can lead to fatal collisions, and some whaling still occurs. We should be inspired to make sure the whales can continue to thrive, because history proves that conservation work can successfully protect these amazing animals!