A

Algae Plants that lack proper stems, roots or leaves. Algae live in water or on the moist surfaces of soil or rocks. Some are microscopic in size while others, including seaweed, can be several metres long. The still waters of ponds and lakes are ideal habitat for algae.

Amphibians Cold-blooded, vertebrate animals that live on land but must return to water to breed. Young amphibians live in the water and breathe using gills. Most adults develop lungs.

Animal A living thing that can sense its surroundings and move independently around. Its body is made of many cells. It gets its energy and nutrients by eating other living things, such as plants, fungus, bacteria or other animals.

Arachnids Types of arthropods that have eight legs. They include spiders, scorpions and mites. They feed by piercing their prey with their sharp fangs, paralysing or killing them with their venom. Their saliva turns the body tissues into liquid that can then be sucked up.

Arthropods Invertebrate animals such as insects, arachnids, myriapods and crustaceans. They have jointed legs and a hard external skeleton, called an exoskeleton.

B

Baleen Plates made of a horn-like material and fringed with fibres, found in the mouths of some whales. These plates strain food from seawater. Baleen whales feed on tiny ocean animals such as krill, shrimp-like creatures. The whales take in mouthfuls of water and filter out the krill through the baleen plates in their mouths.

Birds Warm-blooded, vertebrate animals with four limbs, the front two of which are wings. Birds have a toothless beak and a covering of feathers.

Bivalves Soft-bodied molluscs with two shells joined by an elastic hinge. Bivalves include scallops, oysters and mussels.

Blubber A thick layer of body fat under the skin of marine mammals, including whales, dolphins, seals, sea lions, walruses, manatees and polar bears. Blubber insulates them (keeps them warm) in temperatures as low as 4°C (40°F) and adds buoyancy while swimming.

Bovids A family of hooved animals (ungulates) with bony horns (encased in tough keratin) and hooves that are split into two toes. Cattle, bison, antelopes, gazelles, buffalo, sheep and goats are all bovids. Bovids graze on grass or other plants. All bovids are ruminants: their stomachs are divided into compartments that break down grasses in stages. Most bovids live in herds for protection.

Breeding Also known as reproduction, the production of offspring (young).

Browsers Animals that feed on leaves and twigs from trees and bushes, rather than grasses. On the savanna, the giraffe’s long neck and the elephant’s trunk allow them to eat the highest leaves, while other smaller animals feed lower down.

Burrow A hole or tunnel dug in the ground by an animal. Burrows provide animals with a safe place to live or rear their young. Burrowers include mammals, such as rabbits, birds, such as puffins, and many varieties of insects, spiders and worms.

C

Camouflage The means by which animals escape the notice of predators or prey, using their colours, patterns or body shape to blend in with their surroundings.

Carnivore An animal that feeds on other animals.

Carrion The remains of dead animals.

Cartilage A bendy, fibrous material, also known as gristle. Cartilaginous fish, a group of fish that includes sharks and rays, have skeletons that contain no bone but are made of cartilage instead.

Cephalopods Molluscs with a large head and a beaked mouth surrounded by tentacles. Cephalopods include squid, octopuses, cuttlefish and nautiluses. They are very intelligent and can change colour to scare off predators or blend in with their surroundings.

Cetaceans Carnivorous mammals that live permanently in the water. Whales, dolphins and porpoises are all cetaceans.

Cnidarians A group of jelly-like marine invertebrates with stinging cells which they use to paralyse their prey. Some cnidarians, such as coral polyps and sea anemones, are anchored to rocks with their tentacles pointing upwards. Other cnidarians, such as jellyfish, float with their tentacles hanging down in the water.

Colony A group of one kind of animal living together. Some animals, such as ants, form permanent colonies: these are highly organized with the individual animals carrying out certain jobs that are for the good of the colony as a whole. In some colonies, for example coral reefs, the animals are actually joined to each other. Some mammals, such as seals and walruses, gather in colonies only to breed.

Conservation Efforts to save animals from extinction. These may include the setting up of nature reserves, in which wardens guard the animals against poachers, and breeding programmes at zoos, in which people try to increase the numbers of endangered animals and release them back into the wild.

Constriction A method used by some snakes, such boas and pythons, to kill their prey. They coil their body around its victim and suffocate it to death.

Coral A hard substance formed from the skeletons of tiny animals called coral polyps. These live together in huge colonies in shallow warm waters fringing volcanic islands or rocky coastlines in the tropics. They build up a stony, cup-shaped skeleton around their soft bodies. When they die, the stony casings are left behind. These may build up into huge coral reefs.

Crustaceans A group of arthropods that have jointed limbs and two pairs of sense receptors, called antennae, on their heads. They include crabs, lobsters, shrimp and woodlice.

D

Domestication The taming of wild animals or breeding plants. Domestic animals provide wool, milk, eggs and meat, work on farms, or live alongside us as pets. Crops—domesticated plants—are sown and harvested by farmers.

E

EchinodermsMarine invertebrates with spiny skins and skeletons made of chalky calcium plates. Starfish, sea urchins and sea cucumbers are all echinoderms.

Echolocation The method used by some animals, such as bats and whales, both to find their way around and locate their prey. They emit high-pitched sounds and listen to the echoes to build up a picture of their surroundings.

Endangered A living thing that is danger of becoming extinct. Endangered species have such small populations that they are at risk of dying out altogether.

Exoskeleton The external skeleton of an arthropod. It is made of a light, strong material called chitin, which supports and protects the animal’s body. As an arthropod grows, it moults its exoskeleton and grows a new one.

Extinction The process whereby every member of a species dies out. Extinctions occur naturally, but in recent years, human action has led to a dramatic rise in the rate of extinction of many plant and animal species.

F

Fish Cold-blooded, vertebrate animals that live permanently in water and breathe using gills. There are two main groups of fish: cartilaginous fish, such as sharks and rays, and bony fish, all the others.

G

Gastropods Soft-bodied molluscs, such as snails, slugs and whelks, that move about on one large foot. Some gastropods have hard, protective shells.

Gills The breathing organs of water creatures, including fish and the young of amphibians. They draw water, which contains oxygen, into their mouths. When they pump it out through slits in the side of their head, it passes over the gills. Tiny blood vessels inside the gills extract the oxygen. Bony fish usually have a protective flap over their gills, called the operculum.

Grazers Animals that feed on grasses. Deer, horses and cows are all grazers. They have to eat for much of the day to gain sufficient nourishment.

H

Herbivore An animal that feeds only on plants.

Herd A large group of animals that live and travel around together. Most hooved animals and many other plant-eaters live in herds. The herd offers them some protection, as a large group is more likely to spot predators. Herds move from place to place, according to where fresh grass and water can be found.

Hibernation The spending of winter by some animals in a state of reduced body activity. Their body temperature drops, enabling them to save energy over a long period of time.

I

Insects Arthropods that have six legs and a body divided into three sections: the head, thorax and abdomen. They have a pair of long sense receptors on their heads, called antennae. Flying insects have either one or two pairs of wings.

Invertebrates Animals without backbones. They include insects, arachnids, myriapods, worms, crustaceans, echinoderms, molluscs, sponges and cnidarians.

K

Keratin The material that makes up hair, nails, horns, claws, hooves and the outer layer of human skin.

L

Larva The young of an animal before it goes through metamorphosis. Larvae look very different to adults of the same species. For example, the larvae of many amphibians (e.g. tadpoles, the larvae of frogs and toads) have gills or tails, which are lost when they become adults.

M

Mammals Vertebrate, warm-blooded animals that mostly give birth to live young and feed them with milk. Most mammals have four limbs and a covering of fur, although sea mammals, such as seals, whales and dolphins, have little or no hair and some have lost their back two limbs.

Marine lifePlants, animals and other living things that live in the salt water of the sea, ocean or coastal estuaries.

MarsupialsMammals that do not give birth to fully developed young. Instead, their young are born at a very early stage, and then continue to develop while clinging to their mother’s body, in many cases inside a pouch called a marsupium. Apart from the opossum family of the Americas, marsupials live only in Australasia. They include the kangaroos, wallabies, koala, possums and wombats.

Metamorphosis The process whereby an animal changes its body structure (and behaviour) from being a larva to an adult. In insects, this involves a stage between larva and adult called a pupa.

Migration The movement of an animal or a group of animals from one place to another. Animals usually migrate to find food or to reach conditions more suitable for breeding. Migrations take place over land, by air and by water.

Molluscs A group of invertebrates with soft bodies, often protected by hard shells. The main groups of molluscs are gastropods (snails and slugs), bivalves and cephalopods (squid and octopus).

MonotremesMammals that lay eggs instead of giving birth to live young. There are five species of monotremes: four species of echidna and the platypus. They live only in Australia and New Guinea.

Moulting The shedding of a part of an animal's body, either at certain times of the year, or at a point in its life cycle. This can involve shedding the skin, hair, feathers, fur or wool. Arthropods moult their entire exoskeleton as they grow, while some insects shed their wings.

Myriapods A group of arthropods that includes centipedes and millipedes. Myriapods have long bodies made up of segments, and as many as 300 pairs of legs or more.

N

Nectar A sugar-rich liquid produced by plants. Nectar produced inside flowers attracts pollinating animals, such as mosquitoes, hoverflies, wasps, bees, butterflies and moths, hummingbirds, honeyeaters and bats.

Nest A structure built by an animal in which it cares for its eggs or young.

Nocturnal Active during the night and inactive during the day. In hot areas, animals may be nocturnal to avoid the heat of the day. Some animals, such as bats, hunt at night to avoid competition with birds.

O

Organism Any living thing, including bacteria, plants, fungi or animals.

P

Plankton Tiny plants and animals that float or swim in the surface waters of the ocean. Most ocean animals depend on them, either directly or indirectly, for their food. Animal plankton is known as zooplankton. Plant plankton is called phytoplankton. Algae, simple, single-celled plants, form a major part of phytoplankton.

Predator An animal that kills and eats other animals.

Prehensile Capable of grasping. Some animals, such as some monkeys and many lizards, have a prehensile tail, which they use as an extra limb when climbing through the trees.

Prey An animal that is hunted and eaten by other animals.

Primates A group of mammals that tend to have large brains, forward-facing eyes with sharp vision and dextrous hands (strong, nimble fingers). The group is made up of lower primates (prosimians), such as lemurs, lorises and galagos, and higher primates (simians), which include monkeys, apes and humans.

R

Ratites A group of flightless birds that includes the ostrich, rhea, emu, cassowary and kiwi. Most rattites are tall, running birds that live in open spaces.

Reptiles Cold-blooded vertebrate animals with scaly skins. Reptiles include snakes, lizards, turtles and crocodiles. Most reptiles lay eggs but some give birth to live young.

Rodents A large group of mammals that includes mice, rats and squirrels, as well as beavers, dormice, lemmings and porcupines. All rodents have a set of grinding teeth and a single pair of long, sharp front teeth, called incisors, on both their upper and lower jaws. These incisors grow constantly and must be kept short by gnawing.

RuminantsHerbivorous mammals that get their nutrients from the grasses they eat by fermenting it (breaking it down using bacteria) in their stomach. A ruminant's stomach is divided into compartments for this purpose. After chewing, food passes into the largest chamber of the stomach, the rumen, where the food is converted into balls of cud. The cud is returned to the mouth, where it is chewed and re-swallowed. Cattle, bison, buffalo, goats, sheep, giraffes, deer, gazelles and antelopes are all ruminants.

S

Scavengers Animals that feed on the remains of food killed or collected by other animals.

Species A group of living things that are similar in body structure. Animals of the same species are able to breed together and produce young that can also breed.

Suckling Feeding by a young mammal on milk from its mother. All female mammals have mammary glands which produce milk after their young are born. The young feed on this milk, which gives them all the nutrition they need, until they are able to survive and feed on their own.

T

Tentacle A flexible limb with no bones or joints, belonging to some invertebrates, such as squid and jellyfish. Tentacles may be used for gripping or feeling objects, or for movement.

Territory An area that an animal or group of animals defends against others of its kind to prevent them competing for food. Animals mark their territory by leaving their scent around its borders, or by making loud calls.

U

UngulatesHerbivorous mammals that have hooves instead of claws on their feet. This gives them speed to escape from danger. They are mostly quite large, with strong senses of smell and sight. Ungulates that live in forests or that have to search for their food are often solitary, while those that live in open spaces and feed on abundant plants such as grasses tend to live in herds.

V

Venom A poisonous substance found in the bodies of some animals, including some kinds of snake, spider, scorpion and fish. Venom can be used for killing prey or defence, and is usually injected with a sharp sting or bite.

Vertebrates Animals with backbones. Mammals, birds, reptiles, amphibians and fish are all vertebrates.

X

Xenarthrans (pronounced "zen-AR-thrans") A group of mammals that includes anteaters, armadillos and sloths. These animals have backbones with extra joints to strengthen and support their bodies when they dig. They have few or no teeth.

Z

Zoology The study of animals. Scientists who study animals are called zoologists.

Consultant: Chris Jarvis