Whales & Dolphins   

belong to the order of Cetacea and are mammals adapted to life in water and can be found in all the oceans of the world and a few species in rivers and lakes. Two large suborders of whales exist, the Mysticeti or baleen whales, mostly larger whales including the world's largest mammal, the Blue Whale with 30m in length and 200t of weight, feeding on plankton and the toothed whales of the Odontoceti sub-order feeding mostly on fish and invertebrates. Worldwide some 78 species of whales, dolphins and porpoises are known with some 23 species occurring in the waters of Ecuador. 2 dolphin species inhabit the freshwater rivers and lakes of the Amazon. 

   Whales are the only mammals in the world which adapted completely to water, spending their entire life, from birth to death in this liquid medium. It is believed that the ancestor of whales was a primitive hoofed land animal, which took the plunge some 100 million years ago. Subsequently  the body underwent profound changes to adapt to this new habitat. The hind legs got lost and the front limps evolved into flippers and the broad tail was a new adaptation used mainly for propulsion. The body is protected by a thick layer of fat and their lungs became very efficient with a 80% renewal rate of air with each breath (land mammals have only up to 20% renewal rates). They can take deep dives and can hold their breaths for some 50 minutes.

Marine whales inhabit all oceans of the world with individual species having preferred feeding and breeding grounds. For instance, the humpback whale which breeds in Ecuadorian waters from June to September, spends the rest of the year feeding on plankton in Antarctic waters. Females give birth to one calf which instantly knows to swim and rise for their first breath to the surface. In the beginning they are fed by a rich maternal milk and they grow very fast. Depending on the species young may stay up to two years with the mother and then leaves for a life of its own. Killer whales however are the exception as families stay together.

Many whales were and are still subject to intensive hunting and many species are in really danger of extinction because of that, especially the larger baleen whales. Humans catch them for their meat, oil, bones and other commercial uses. Whaling has a long history and as an industry dates back to the 9th century. In many waters they became rare and whalers searched for them in ever more remote areas. In the Galapagos, American whalers were active in the 19th century taking many species. Apart from commercial uses, species are also taken for scientific reasons and to perform in so-called sea-world shows to entertain people or being put on display in zoos.

Location

Note: The above species are only a selection of the most common ones found in the Pacific ocean around the coast of mainland Ecuador and Galapagos islands. In the freshwater rivers and lakes of the Amazon exist only those two last species.

Mammal Vocabulary