While floating motionless, part of the head, the dorsal fin or parts of the back are exposed at the surface. Gray whales make the longest seasonal migration of any of the whales. They travel about 12,500 miles each year. The strongest social ties are between mother and calf. A social group of whales is called a pod .
Baleen whales travel alone or in small pods.
The toothed whales travel in large, sometimes stable pods. The toothed whales frequently hunt their prey in groups, migrate together, and share care of their young. Cetaceans breed seasonally, usually in warm tropical waters, and females usually have one calf every 1-3 years. The gestation times range from 9-18 months. Whale calves can swim at or soon after birth.