What imparts the Behaviour in living bodies?

          Many animals, from earthworms to whale sharks, lead simple lives. Their behaviour is limited and they only encounter others of their kind briefly to mate. Other creatures have much more complex behaviour. They form groups, have contests for group supremacy, mates and territories, help each other when feeding and even look after each other’s offspring.

          Living things strive to survive so that they can breed and pass on their genes to their offspring. An animal must choose its breeding partner carefully. Courtship behaviour and mating displays pick out a partner of the same species, the opposite sex, sexually mature, strong, fit and healthy. This increases the chances of the offspring being fit and healthy, too.

          In some animals, survival depends on having a territory. This is a patch of land or water where the owner can live and feed without being in direct competition with rivals of its own kind. Owners often mark their territories by rubbing scents, spraying urine and leaving piles of droppings around the borders. They defend the territory against other of their kind by calls and songs, and also by visual displays.

HELPING OTHERS

          Life in the wild is a battle to stay alive. But sometimes helping others can increase an individual’s own chances of survival. Some living things form partnerships with other, quite different species where both partners gain. This is known as symbiosis. Cleaner fish are small fish, such as wrasses, that tend to larger fish. The big fish could easily eat the cleaner. But the cleaner nips fish lice and other pests from its body, mouth and gills. The big fish is relieved of these parasites and the cleaner fish gets its meal.

          The hermit crab forms a symbiotic partnership with the calliactis sea anemone. The anemone protects the crab with its stinging tentacles. In return the crab carries the anemone to new places to catch victims. Also each partner may share in the leftovers of the other’s meal.

          Many group-living animals produce alarm calls and actions if they spot danger. This warns others in their group. Likewise if one group member finds a plentiful supply of food, the others gather round to share it. A few kinds of animals even work together to hunt prey. These co-operative killers include wolves, lions and African wild dogs.

Picture Credit : Google