For the most part, whales are visible only when at the surface breathing – less than 20% of the time – so it is inherently challenging to document and study whale behavior.
Baleen whales are generally found singly or in loose associations, not in large groups or families. Exceptions include migrating baleen whales, which may be found in small groups of several individuals, and large numbers of individuals that may congregate in feeding or calving areas.
All species of baleen whales establish strong mother/calf bonds. In fact, the strongest apparent bond between two individuals is between a calf and its mother.
- Mother and calf stay in close physical contact throughout the nursing period. A mother baleen whale stays close to her calf and attentively directs its movements. The baby swims close to its mother and is carried in the mother's "slip stream", a type of hydrodynamic wake that develops as the mother swims.
- A mother whale may teach her calf certain behaviors.
- Whalers noted that female whales became aggressive when protecting their young.
Research into baleen whale behavior is ongoing. Some behaviors may be interpreted as being related to food-gathering, aggression, excitement, warning, visual inspection, or mating.
- Some baleen whales slap their pectoral flippers, tail flukes, or head on the surface of the water, which creates loud sounds under water.
- Calves and adults have been seen pushing around objects such as logs, kelp, and debris.
Whale watchers and researchers have named certain common whale behaviors.
- A breach is a behavior in which a whale powerfully thrusts a large part of its body out of the water and lands on the surface - usually on its side or on its back - with a huge splash. Sometimes the same whale will breach several times in sequence.
- A spyhop is a behavior in which a whale rises out of the water somewhat vertically, exposing its head.
Various baleen whale species show characteristic behaviors.
- Gray, fin, minke, bowhead, and right whales commonly breach and spyhop.
- Bowhead and right whales exhibit head- and body-slapping.
- Humpback whales may be the most acrobatic species of baleen whales. They breach, spyhop, charge other whales, stroke other whales' flippers and flukes, and slap their flippers and tail flukes on the water's surface.