For example, sometimes the escort male will blow bubbles to create a sort of underwater screen. As the female swims through the wall of bubbles, she briefly disappears from view. The escort male uses this moment to divert her direction and shake his competitors from her path. Group associations are pretty fluid within the population of whales. Observers will see males associate with a group and then dissociate with a group when they get tired or are just ready to give up.
Humpbacks gather into larger feeding groups and work together to surround and catch prey.
The whales then take turns plunging through the column of fish, filling up their mouths with fish and seawater. Like all other baleen whales, humpbacks feed by taking in large mouthfuls of seawater and fish. They strain the water through their baleen and swallow the fish that remain in their mouths. It seems odd that these huge mammals measuring over 40 feet long and weighing more than 80 tons on average eat such small prey. But, if you think about it, feeding at the bottom of the food chain permits them to consume the biomass they need, especially since the small fish and krill they eat are incredibly abundant in the northern waters where humpbacks feed.