Many baleen whales are endangered from over-hunting. Baleen whales have baleen plates instead of teeth, which they use to filter small particles of food. Baleen is a series of stiff, flexible material that hang from the upper jaw. Many baleen whale species migrate seasonally from cold-water feeding grounds to warm water breeding grounds. Many species congregate in groups called pods.
Many species sing songs but they lack echolocation capabilities.
Baleen whales have symmetrical skulls. Concentrated masses of prey are preferable for this method of feeding. Gulpers include most rorquals, blue whales, pygmy blue whales, fin whales , Bryde's whales, humpback whales, and minke whales. Skimmers - these whales keep their mouths open most of the time, filtering food all the while. Sei whales do both.