A4: Innate and Learned Behaviour

Innate Behaviour Develops independently of the environmental context; it’s in the genes and is inherited! (Nature – not nurture) A behaviour that occurs in all members of a species including young and inexperienced animals. Genes controlling innate behaviour are naturally selected.

Innate Behaviour Ex: Infants, suckling, grasping objects Ex: Birds migrating south Ex: Spiders spinning a web correctly the first time.

Taxes and Kinesis (movement) responses to stimuli Taxes and Kinesis are examples of innate behaviour TAXES: directional response to stimuli KINESIS: nondirectional response to stimuli

Taxes Stimulus: light, sound, electricity, chemicals Ex: Euglena is a photosynthetic, motile, unicellular organism. It will move toward light This is a positive phototaxis (If an organism moved away from light, that would be a negative phototaxis)

Types of Taxis Chemotaxis: response to chemicals in the environment I.e.: pH levels, drugs, food, pesticides… Phototaxis: response to light Gravitaxis: response to gravity Rheotaxis: response to water current Thigmotaxis: a response to touch

Kinesis Stimuli: gas levels, humidity, air pressure, ambient temperature…. The rate of movement of the animal depends on the intensity of the stimuli and not it’s directional Ex: Woodlice are know to show kinesis to humidity They dry out if they remain in dry conditions They move faster and turn around more often in dry conditions than in damp ones (because they are trying to get out of the uncomfortable dry environment)

Learned Behaviour Is the result of an experience It is not inherited, and not controlled by genes. Not the result of natural selection. It’s nurture, not nature. Develops by response to an environmental stimulus

Learned Behaviour Offspring learn behaviour patterns from their parents and other individuals in their environment. Ex: humans and language An animal will repeat a particular behaviour if it is rewarded by it. Learned behaviours also depend on genes (humans can’t talk without the presence of specific language genes) Learned behaviours develop because of the result of the experience and innate behaviours develop independent of it.

Birdsong Example of a behaviour that is both innate and learned Singing is a genetic trait of birds – an innate behaviour Song birds will sing a simple song if not taught by other birds However, through experience, they can expand their song (from hearing other birds or other noise devices) https://www.youtube.com/watch?v=ocCPvl6mUmo (skip to 0:40 if short on time)

Reflex Conditioning Reflex conditioning involves forming new associations by establishing new neural pathways in the brain. Conditioned reflexes are used extensively in animal behaviours and can greatly increase survival chances. Ex: Birds have an innate reflex to avoid food with bitter tastes, but need to learn which insects will have that taste. If they eat a black and yellow striped bug that is bitter, it will learn to avoid eating them.

Pavlov’s Dog 1920’s: psychologist Ivan Pavlov conducted experiments on conditioned behaviours. Premise: Animals salivate when they smell or taste or see food. Question: Can a behaviour such as salivation be conditioned?

Pavlov’s Experiments When a dog smells or tastes or sees food, it will automatically salivate. The food is an unconditioned stimuli. In his experiment, Pavlov would ring a bell every time he’d feed his dogs. The dogs would become conditioned to associate the sound of the ringing with food.

Pavlov’s Experiment As a result, after continuing this pattern, the dogs would salivate every time they heard a bell ring – even when food was not provided – because they anticipated food. Hence, they were conditioned to salivate. Office clip: https://vimeo.com/35754924

Operant Conditioning Operant conditioning is a form of learning which consists of trial and error experiences. Reflex conditioning is initiated by the environment imposing a stimulus on the animal. Operant conditioning is initiated by an animal spontaneously testing out a behaviour pattern and finding out what its consequences are. The behaviour is reinforced or inhibited based on the consequence.

Operant Conditioning Ex: Lambs learn not to touch electric fencing by operant conditioning. Big Bang Theory http://www.youtube.com/watch?v=Mt4N9GSBoMI

Imprinting Imprinting is learning occurring at a particular life stage and is independent of the consequences of behaviour. Famous example of imprinting comes from scientist Konrad Lorenz who in the 1930s experimented with greylag geese and their goslings.

Imprinting Eggs are normally incubated by their mother. When the eggs hatch, their mother is the first large moving object they see. The goslings follow their mother around during the first few weeks of life and she leads them to food and protects them. The goslings have imprinted on their mother.

Imprinting Lorenz showed that when young geese are hatched in an incubator, their mother isn’t the first large moving object they see. So they attach themselves to another large, moving object. This could be another bird, another animal, or even a human The attachment is “imprinting”.

Imprinting For the greylag geese, imprinting occurs 13-16 hours after hatching. Note: Imprinting is independent of the consequences of the behaviour. Animals remain imprinted on something even if it does not increase their chance of survival. https://www.youtube.com/watch?v=ihh1xBXwt_0

Learning Learning is the acquisition of skill or knowledge. The behaviour of animals changes during a lifetime. Some behaviour patterns are lost (palmar grasp reflex of infants) and many more a learned. Learning is a higher order function of the brain and humans have a greater capacity to learn than any other species. The degree of learning is dependent on their longevity, their neural capacity, their experiences, and their social interactions.

Research Methods in Animal Behaviour Laboratory experiments and field investigations have helped in the understanding of different types of behaviour and learning. With laboratory experiments, variables can be controlled more effectively and innate behaviours in particular can be investigated well. However, animals often do not behave normally when removed from their environment, especially with learned behaviours.

Invertebrate Behaviour Experiment In 2 weeks, in small groups, we will be observing and analyzing the behaviour of invertebrates in response to a stimulus. You will be observing either a taxis (a directional response to a stimulus) or a kinesis (a change in the rate of movement) The organisms you will be working with….

Planaria (Dugesia tigrina) Flatworms living in lakes or ponds. Quite active They have a simple nervous system, and two eye spots (photoreceptors) Also have chemoreceptors

Earthworms (Lumbricus terrestris) Sensitive mechanoreceptors. Does not have eyes, but do have photoreceptors

Water Flea (Daphnia magna) Very sensitive to changes in water temperature and pH. Their heart beat can be seen by observing contractions of their body under a microscope or a magnifying lens.

Euglena acus Protists. Photosynthetic (have photoreceptors!) Have a flagellum