Cetacean Society International

Working for whales, dolphins and porpoises worldwide

CSI Photo Gallery

Chilean Dolphin

(Cephalorhynchus eutropia)

The Chilean dolphin has a beautiful, subtle and complex color pattern, including an unusual white area just at the base of the pectoral fins. The streaming water gives some clues about the efficiency of the body and fins, and the sheer power of this fast swimming dolphin's flukes. But here it's the dolphin's eye that stands out, as the dolphin rushes by with a surge at the surface. Is the dolphin curious about the scientist taking the picture? Chilean dolphins seem to prefer rapid tidal flows and rips, probably for hunting, but perhaps their natural predators don't like those conditions, or the water noise and turbulence hides them from natural dangers. Strong and fast, they are at home even in turbulent waters near rock walls, as here, where they may find small crustaceans. They also eat schooling fish and squid. (Photo courtesy of Francisco Viddi Carrasco, Chile)
These leaping Chilean dolphins could be very excited, or scared, or just in a hurry. Like other dolphins that are well adapted for fast swimming, they probably can swim like this for short distances at about 20 mph (33 km/h). To escape a predator they can swim even faster, but not very far before tiring. Normally they can swim almost continuously, without needing high-energy leaps, and travel long distances at 4-6 mph (10 km/h). As they swim faster the drag from the water increases, until they can't go any faster no matter how strong they are. It's thought that leaping out of the water like this helps dolphins travel faster for the moment they are out of the drag from the water. That drag is highest at the surface, where dolphins need to breathe, and lowest about three body widths below the surface. So what we may see here is each dolphin rushing up through the surface to breathe very quickly, and diving again to a low drag depth. (Photo courtesy of Francisco Viddi Carrasco, Chile)
Because the Chilean dolphin was so unknown until just a few years ago, and scientists only saw distant dolphins, or dead ones that quickly turned almost black, the species was mistakenly called the black dolphin. Today local scientists combine sophisticated techniques with local knowledge, providing a great burst of information on this elusive species. Some populations may migrate seasonally, others stay in one area year-round, and something new is learned every day! It's very exciting today for scientists studying these dolphins, and CSI is excited about helping them. (Photo courtesy of Julio C. Reyes, Peru)
Some of the dolphins killed incidentally in fishing nets are used for crab bait in southern Chile. Some are trapped, harpooned or shot illegally for that purpose, or human consumption. The complex of islands and channels makes enforcement and protection against this black market impossible. They are far more wary of boats in the south than they are in the north, probably because they know what it is to be hunted. The increasing salmon aquaculture industry may be invading Chilean dolphin habitats as well. (Photo courtesy of Francisco Viddi Carrasco, Chile)
This Chilean dolphin calf shows vertical lines called fetal folds. They are creases left over from before he was born, when he was tightly curled inside his mother. His mother is only 1.6 meters long, and weighs only 57 kilograms, but he's not as tiny as you might think. As local scientists develop sophisticated techniques and become familiar with the groups near them, this calf may be accommodated to these scientists, and they may follow him through his whole life! (Photo courtesy of Francisco Viddi Carrasco, Chile)
Showing the distinctive rounded dorsal fin and general body contours characteristic of all dolphin species in the Cephalorhynchus genus, this breaching Chilean dolphin also shares the often-boisterous spirit shown by the others. Like other fast swimmers, they also can turn so quickly that scientists have calculated peak loads of over 3 g's! This is similar to the forces on a jet fighter while turning! With widely separated, generally coastal ranges in Latin American, Africa and New Zealand these dolphins must have had a common ancestor, but what did it take to make this ancestor spread out across wide ocean basins? (Photo courtesy of Francisco Viddi Carrasco, Chile)