THE SECRET
Humpback whales, our most common sights, are incredible animals to observe and while they're much known for their fluking behaviour right when going down for a dive, the most distinctive physical feature are actually their long pectoral fins.
Not as much visible as their tail, which is usually lifted out of the water as the whale prepares for its next dive, the pectoral fins or so-called flippers can be seen to the sides of the whale's body, right below the surface - remember to have a close look when at sea with us!
These pectoral fins are with a length of up to 5 metres (or a third of the whale's body length) not only the longest among all species of cetaceans, but in fact the longest appendages of all animals on our planet. Even the Latin name "Megaptera novaeangliae" of the humpback whale refers to these unique flippers: "mega" meaning big and "ptera" wing.
Thanks to the length of these flippers, the humpback whale is very agile in the water and is capable of manoeuvring way better than other cetaceans of its size: it's able to make sharp turns, quickly roll over or change course completely within seconds.
Further, these fins are equipped with patterns of tubercles (knobby humps), which are unique to humpback whales and found on other body parts as well. These tubercles help direct the water flow over the fin, making the fins and the movements of the animal even more efficient. Each of these tubercles contains a single, stiff whisker-like hair that is connected to a dense network of nerves. It's yet to be uncovered what the exact purposes of these hairs are, however, among others, they are believed to improve the efficiency of the humpbacks' swimming.
Last, humpback whales seem to benefit of these large flippers when feeding as they use them to gather and steer prey to their mouth. It appears that their pectoral fins turn out helpful to better concentrate the prey they're going for, especially when involved in bubble net feeding (another feeding technique unique to humpbacks in which they exhale air under water to create nets of bubbles that trap their prey and then direct it towards the surface), which in turn increases the amount of food ingested at once. This feeding technique is also called "pectoral herding".
- Sarah