Acoustic: relating to sound. A cetacean’s primary sense is hearing and they rely on sound to communicate with each other, navigate around their environment and to find food.
Baleen: comb-like bristles that hang from the upper jaws of most of the largest whales. Baleen is used by whales to filter their food from the water. Hence the term ‘baleen whales’.
Blow: the cloud of water droplets and mucus that comes from a cetacean’s blowhole when it breathes out. Also known as a ‘spout’.
Blowhole: a cetacean’s ‘nostril/s’ on top of its head. Cetaceans with teeth have one blowhole, cetaceans with baleen have two blowholes.
Blubber: the layer of fat just under the skin that helps keep a cetacean warm and provides an energy store for them.
Bow-riding: riding on the pressure wave in front of a boat or even a large whale.
Breaching: when a cetacean leaps out of the water, often landing back on their side with a splash.
Bycatch: the unintentional capture of animals in fishing nets, such as dolphins in trawl nets and porpoises in set nets.
Calf: a baby/young cetacean that is still being nursed by its mum.
Captivity: holding cetaceans (and other animals) in zoos/aquariums/sea pens etc so that they are not free.
Cetacean: the collective word for all whales, dolphins and porpoises.
Climate Change: this term is commonly used interchangeably with "global warming" and "the greenhouse effect," Climate change refers to the build-up of man-made gases in the atmosphere that trap the sun’s heat, causing changes in weather patterns on a global scale.
Dolphinarium: an aquarium for dolphins. Plural is dolphinaria.
Dorsal fin: the fin on the back of a cetacean.
Drive Hunt: a method for hunting dolphins and other small cetaceans, mainly in Japan, using a boat and nets to drive them towards the shore where they are killed for their meat or captured for dolphinariums. Thousands are killed each year.
Echolocation: the system used by most cetaceans to find food, navigate and communicate by sending out clicks and using the echo that comes back to create a ‘sound picture’. Sometimes referred to as ‘sonar’.
Entanglement: when a cetacean (or other animal) gets caught up in fishing gear, often rope or netting.
Foetal Folds: light banding or stripes that run around the body of a very young calf, marking where the baby was folded up inside its mum’s womb.
Flipper: also known as ‘pectoral fins’, they are the fins on the side of a cetacean.
Flukes: a cetacean’s tail fins.
Habitat : a place where a cetacean (or other animal) lives.
Habitat Degradation: damage to a habitat, for example from chemical pollution
Harassment: persistent disturbance of a cetacean so that it is unable to behave naturally.
Krill: little shrimp-like animals that are eaten by other animals including blue whales, the largest animals on Earth.
Lobtailing: when a cetacean slaps its flukes hard against the surface of the water. Also known as ‘tail-slapping’.
Logging: floating still at the surface of the water.
Migration: when animals move into different regions at different times of the day or year. Plankton vertically migrates in the water column depending on sunlight. Some whales migrate from colder to warmer waters seasonally.
Neonate: a newborn infant.
Photo-identification: identifying individual animals from photographs of markings on their bodies, usually on their dorsal fins or flukes.
Plankton: animals and plant-like organisms that are usually tiny and depend on the ocean currents for movement and are eaten by some cetaceans.
Pod: a group of cetaceans. Often the word ‘pod’ is used for toothed whales (cetaceans with teeth rather than baleen).
Population: a distinct group of animals of the same species.
Prey: animals that are eaten by other animals, like the fish and krill that whales feed on.
Rorqual whales: baleen whales that have throat grooves. Minke, Brydes, Humpback, Sei, Fin and Blue.
Spyhopping: when a cetacean raises its head above the water’s surface to look around.
Stranding: when one or more cetacean/s comes onto land, either live or dead.
Tail-slapping: when a cetacean slaps its flukes hard against the surface of the water. Also known as ‘lobtailing’.
Temperate zones: the parts of the Earth between either the Tropic of Cancer and the Arctic Circle or the Tropic of Capricorn and the Antarctic Circle.
Threats: the dangers that cetaceans (and other species) face.
Tropical zone: the part of the Earth between the Tropics of Cancer and Capricorn; characterised by a hot climate.
Whaling: the deliberate hunting and killing of whales.