The humpback whale is perhaps the most numerous of the big whales in Canadian waters. It enjoys a vast distribution along both Canadian coasts and indeed worldwide. The humpback earned its name by the hump that breaches from the water prior to sounding. The humpback is extremely gregarious, traveling in groups of up to 150 individual whales. It is very playful and is often seen breaching from the water and diving back in head first, slapping the water with its flukes, or doing underwater acrobatics. Humpbacks are also very curious and docile and will approach divers and boats to inspect them. In the winter they will migrate from the frigid arctic waters to warmer waters. Humpback whales are primarily filter feeders but will also feed on some fish and even some small birds when the opportunity arises.