Digestive system of humpback whales stretching like an accordion. They allow whales to open their mandible to 90 degrees to gulp water and prey. They expel saltwater through the baleen plates, leaving behind krill and plankton. The whale's tongue plays a vital role in filter feeding, as it is used to push the water out of its mouth while keeping the prey trapped in its baleen bristles. As humpback whales do not have teeth, their food is swallowed whole and travels down the esophagus into the preliminary stomach (known as the forestomach) to be ground. Baleen whales have a multi-chambered stomach, divided into three distinct
Michael Bigg key discoveries of Dr. Bigg's team was that there were two types of killer whales living near the British Columbia coastline: "residents" which ate almost exclusively fish, and "transients" which hunted marine mammals and other warm-blooded prey. Resident and transient killer whale societies are separate, and the two types tend to avoid each other. The resident killer whale population of British Columbia and Washington is further divided into two "communities", one northern and one southern, that do not interbreed. Another discovery was that resident killer whales have one of the most stable social structures of any animal species. Pods of