Humpbacks are one of the best studied large whales and their habits of displaying a wide range of different acrobatic behaviors make them a favorite among whale watchers. Humpbacks have also become widely known because of their complex songs, consisting of a series of repeating patterns, which are used as part of the males breeding display in the competition for access to females.
While humpbacks generally occur mainly in smaller groups or as single individuals, they may gather in large numbers at their feeding- and breeding-grounds. The only known long-term bond between humpbacks is that of mothers and calves, where the calf generally stay together with its mother for about one year. The calves are born in warm, comparatively shallow, waters in the tropics and then follow their mothers on the migration to the northern feeding grounds. Calves typically become independent in route or while on the feeding grounds but may accompany their mothers back to the breeding grounds.
Compared to other baleen whales, humpbacks show a lot of themselves above the surface and a number of different behaviors may be observed in the encounter with the whales. Some of the most commonly observed behaviors are listed below.
The blow, or “spout” of the whale is usually the best way of locating large whales and probably the first thing you will observe at sea. Being mammals, humpbacks need to come up to the surface to breathe and when the whales exhale, a bushy blow of condensed air is seen. The blow of a humpback is typically around 3 meters high, depending on the weather and wind conditions, and a humpback typically blow 3 to 6 times in a row at ca 10-20 second intervals between the blows.
Humpbacks may be seen lying motionless at the surface, usually facing the same direction. This is known as "logging” and is a kind of rest or “sleep”.
Many large whales lift their tail flukes into the air before diving, usually before a deeper dive. This is called fluking and humpback whales usually always lift their tail flukes before a dive. Humpback flukes, with their black and white markings on the underside of the flukes are unique.
Humpbacks have exceptionally long flippers (or pectoral fins) being up to 5 meters in length which correspond to one third of the animals total length. While rolling over at the surface, humpbacks may sometimes slap their flippers onto the water with a huge splash or otherwise lie on their backs and wave both flippers in the air.
Tail-slapping (sometimes also known as lob-tailing) is when the whale lifts the tail fluke high out of the water and then slapping the water with it, often repeatedly and with force. The reason for tail-slapping is debated but may be used in communication, as an aggressive behaviour or may be used to stun the prey while feeding.
Spyhopping is a wonderful behavior to observe. As the name implies, this behavior involve the whales simply sticking their heads out of the water as if to look around above the water surface. Maybe this is what they do as they often poke their heads high enough up so that the eyes are above the water surface, but equally often only the rostrum (nose) can be seen.
Breaching is undoubtedly the most spectacular behavior that can be observed and involves the whale leaping clear out of the water and landing with a huge splash. Sometimes full breaches can be observed, often repeatedly, but often half-breaches are observed where a large portion, but not the whole body of the whale, emerges above the water. Why large whales breach has been discussed for a long time. Reasons may include communication, ridding themselves of barnacles or else simply having the time of their life.
At their feeding grounds, humpbacks can sometimes gather in large numbers to herd and capture their prey and they have many different feeding techniques. Most widely known is perhaps the so called bubble-net feeding technique that has been observed in, for instance, Alaska. Whereas similar looking techniques have been observed in our area, we do not know of any case where actual bubble-netting have been used. More commonly is that they lunge through patches of prey and filter out the prey from large mouthfuls of water, sometimes in coordinated groups of up to ca 10-15 animals. When this happens, their prey (in our area herring) is forced to the surface and may be seen jumping to escape the humpbacks large mouths.