‘100 Facts You should Know: Whales and Dolphins’ (II)
This week, we’ll continue with the remaining parts of ‘100 Facts You should Know: Whales and Dolphins’ by Steve Parker.
9. Whales, dolphins and porpoises have very sensitive skin. They rub and stroke others in their group, or a partner during breeding time. A mother whale often caresses her baby to provide comfort and warmth.
10. Whales, dolphins and porpoises don’t have outer ears. Instead, sounds in the water are detected inside the head. Many toothed whales find their way in dark water by making clicking sounds, then listening to the echoes that bounce off nearby objects. This method is called echolocation.
11. Many cetaceans feed near the surface, so do not need to dive more than 50m down. The champion diver is the sperm whale. It can go down 3000m to hunt its prey of giant squid.
12. Dolphins, porpoises, and toothed whales are active hunting carnivores. They eat meat — — the flesh of sea creatures, especially fish and squid. Some of them crunch up hard-shelled crabs, shrimps and prawns, or shellfish, such as oysters and whelks.
13. Many cetaceans migrate to find food at the same time each year. Baleen whales spend summer in cold northern or southern waters where there are vast amounts of food. For winter they swim back to the tropics. Although there is little food there, the water is warm and calm.
14. The killer whale can kill and eat almost any creature in the sea, from a small fish to a large whale. It is also known as the orca. It is not actually a whale, but the biggest member of the dolphin family.
15. Many dolphins like to bow-ride. This means riding in the bow wave of a ship or boat — — the v-shaped wave made by the boat’s sharp front end slicing through the water. Exactly why they do this is not clear.
16. Porpoises (鼠海豚/江豚)are in a different subgroup than whales and dolphins. There are six species that are all found in the sea. Most live in shallow water near coasts and shores. Porpoises have spade-shaped teeth, whereas dolphins have cone-shaped teeth.
