Cetacea toothed whales and two in baleen whales. The nostrils are located on top of the head above the eyes so that the rest of the body can remain submerged while surfacing for air. The back of the skull is significantly shortened and deformed. By shifting the nostrils to the top of the head, the nasal passages extend perpendicularly through the skull. The teeth or baleen in the upper jaw sit exclusively on the maxilla. The braincase is concentrated through the nasal passage to the front and is correspondingly higher, with individual cranial bones that overlap. In toothed whales, connective tissue
Captive killer whales they are successful, and withholding it when they are not. Secondary reinforcement—things not essential to life, such as play time, tactile rewards and fun games—can also be used as rewards. The practice of keeping killer whales in captivity is controversial, and organizations such as World Animal Protection and the Whale and Dolphin Conservation campaign against the captivity of killer whales. Orcas in captivity may develop physical pathologies, such as the dorsal fin collapse seen in 80–90% of captive males. The captive environment bears little resemblance to their wild habitat, and the social groups that the killer whales are put into