The whales are cetaceans, warm-blooded mammals that breathe through lungs and give birth live. The Southern Right Whale has no teeth and relies on its baleen, a series of flexible laminates that filter water to feed off diminutive crustaceans - called krill. Krill are found in abundance in waters off Antarctica where the whales spend most of the year feeding. While off the Valdes Peninsula, the whales subsist on the body fat stored up during the previous months. Many pull out cameras as Moby Dick draws close enough for an American tourist to point out the thickened yellowish calluses on the head - typical identifying patterns.
Every whale has a unique pattern, much like fingerprints in humans.
Scientists have even been able to conduct aerial surveys tracking the movement of individual animals by their markings. Whale-watching, while closely regulated, has grown over the years. In the past, smaller boats made the expeditions with just a few people at a time. Now catamarans and larger vessels accommodate dozens of tourists on a single outing. Some 100,000 tourists a year now make the trip.