V.C.E. Biology Unit 2 Animal Behaviour

What is behaviour? Individual behaviours are those related to the movement of an animal or its physiology. Such as foraging for food or panting in dogs. Social behaviours are those related to the interaction between individuals such as courtship displays in Lyrebirds or the imprinting of chickens and ducks. Behaviours are coordinated activities in response to internal or external stimuli – flight from a predator, searching for a mate in spring or searching for food when hungry.

What is behaviour? Some behaviours are innate. That means that we are born with them and they have been passed down in our genetic material from our ancestors. An innate or instinctual behaviour is caused by a releaser – a stimuli of some sort. They can be visual, auditory or chemical. Mother hens respond to the call of their chicks, while male sticklebacks attack red patches on the bellies on other sticklebacks invading their territories.

Learning Other behaviours need to be learnt – this is very true of humans. Learning means that the organism modifies a behaviour on the basis of a prior experience. This requires memory. So animals with nervous systems and brain stems are capable of this. The ability to learn is an indication of intelligence. So generally the vertebrates are most likely to show this ability, but some of the invertebrates are also able to display learning.

Learning Imprinting – in some animals the learning period is a short stage often just after birth. Ducklings and chickens will accept the first object they see as their mother and are bonded to that object for life. Habituation – involves the general fading of a response. A stimuli may cause a particular response, but as the animal learns that the stimuli is harmless the response diminishes.

Learning Associative learning – or conditioning – is when a certain behaviour can be caused by associating it with a certain stimuli. You jingle your keys before taking the dog for a walk. The sound of the jingle is always seen as an invitation to go for a walk. Trial and error learning – this is when we learn things by trying them out. Mistakes cause us to correct our behaviour and improve our performance of the task.

Behaviour for maintenance Patterns of behaviour are generally adaptive, so that they benefit the organism in some way. Circadian rhythms – these are periods of activity and inactivity related to the daily cycles of night and day Lunar cycles – these are cycles of activity based on the moons cycles – such as feeding and mating related to the full moon Circannual rhythms – cycles such as the animal migration of whales down the east coast of Australia

Behaviour for maintenance Movement – animals move to find shelter or new nest sites, food, water, interact with other animals. Feeding – animals have many behaviours related to successful collection of food. Sea Otters collect oysters which they then break open on rocks. Avoiding capture – herbivores looking for food have to avoid capture themselves. Homeostatic – animals need to maintain a constant core body temperature. Some reptiles will do this by basking in the sun on warm days and hibernating in hollows on cooler days.

Behaviour for maintenance Grooming – to maintain a clean, disease free coat animals such as birds, cats and dogs have elaborate bathing, preening and grooming behaviours – in some monkey species these become part of the family hierarchical behaviour Home-building – Spiders build webs, birds make nests, ants and bees have elaborate nests – these behaviours tend to be innate. Territorial – Many animals, especially carnivores defend feeding and/or mating territories from other members of the same species to ensure their own survival.

Behaviour for communicating Many behaviours allow animals to communicate with members of their own species and with other species. Pheromones – are a chemical means for achieving this. Pheromones are released by the animal and tell others that they are on heat, or angry, or it’s their territory etc. Visual – many male birds have colourful plummage and do elaborate dances to attract mates. Sound – sound can be used to attract other animals of a group, sound a warning that a predator is near or to mark territory against invaders.

Behaviour for communicating Touch – can be used to maintain social hierarchies (Baboons grooming) and to maintain contact between members of a population (Ants foraging away from the nest). Cultural – much of our human learning falls into this area of cultural behaviour with important information being passed down from generation to generation.