Coping With Dangers Chapter 26

Avoidance Behaviour & Habituation Avoidance behaviour is an escape response – unlearned behaviour Avoidance behaviour is an escape response – unlearned behaviour E.g. snail retreats into it’s shell if tapped E.g. snail retreats into it’s shell if tapped - eventually snail doesn’t react - eventually snail doesn’t react This is learned behaviour – habituation This is learned behaviour – habituation Habituation is short lived Habituation is short lived Animals can be motivated to respond to a stimulus Animals can be motivated to respond to a stimulus

Learning Experiments Humans can improve their performance in basic tasks through practice Humans can improve their performance in basic tasks through practice Eventually a maximum performance will be reached Eventually a maximum performance will be reached This can be represented on a learning curve This can be represented on a learning curve Learning can often provide a long-term modification of behaviour Learning can often provide a long-term modification of behaviour Depends upon animal being capable of remembering Depends upon animal being capable of remembering

Learning to avoid danger Toads Toads - will snap at any insects - will snap at any insects - if it snaps at a bee and gets stung, it avoids striped insects - if it snaps at a bee and gets stung, it avoids striped insects Birds Birds - Hatched ducks/goslings follow first large object that moves and makes sounds - Hatched ducks/goslings follow first large object that moves and makes sounds - this is normally in response to mother - this is normally in response to mother - this early life experience is imprinting - this early life experience is imprinting - has a significant survival value - has a significant survival value Humans Humans - educated by and imitate more experienced elders - educated by and imitate more experienced elders - Learn hazard signs/green cross code - Learn hazard signs/green cross code - often trial and error improves learning - often trial and error improves learning Intelligence, and use of reasoning, affects ability of animal to learn Intelligence, and use of reasoning, affects ability of animal to learn

Individual mechanisms of defence Active Active - Skunks produce foul-smelling secretion - Skunks produce foul-smelling secretion - Insects & reptiles inject poisons - Insects & reptiles inject poisons - Antelope & ostrich use long legs to flee - Antelope & ostrich use long legs to flee - many animals withdraw into cover e.g. octopus - many animals withdraw into cover e.g. octopus - birds employ distraction displays - birds employ distraction displays - some animals feign death – e.g. grass snake - some animals feign death – e.g. grass snake Passive Passive - protective coverings – e.g. shells, spines, bristles - protective coverings – e.g. shells, spines, bristles - markings e.g. ‘eyes’ on moth wings - markings e.g. ‘eyes’ on moth wings - colouration & poisonous chemicals – e.g. kokoi frog - colouration & poisonous chemicals – e.g. kokoi frog - camouflage – e.g stick insects, hoverfly - camouflage – e.g stick insects, hoverfly - flounder and trout blend into environment - flounder and trout blend into environment - butterfly fish has deflection display - butterfly fish has deflection display

Social mechanisms for defence Many species rely on ‘safety in numbers’ Many species rely on ‘safety in numbers’ E.g. schools of fish, herds of mammals, flocks of birds E.g. schools of fish, herds of mammals, flocks of birds Musk Ox Musk Ox - no hiding places (barren environment) - no hiding places (barren environment) - under threat, form a protective group – this is mobbing - under threat, form a protective group – this is mobbing Quail Quail - Roost in circles – heads facing outwards - Roost in circles – heads facing outwards - ‘explode’ into predators face - ‘explode’ into predators face Baboon Baboon - dominant males stay central – close to infants/females - dominant males stay central – close to infants/females - lower ranking males keep to the edge - lower ranking males keep to the edge

Defence in plants Structural Structural - thorns (modified side branches) e.g. hawthorn - thorns (modified side branches) e.g. hawthorn - spines (reduced leaves) e.g. gorse, cacti, holly - spines (reduced leaves) e.g. gorse, cacti, holly - more spines nearer the ground - more spines nearer the ground - stings e.g. nettle - stings e.g. nettle Ability to tolerate grazing Ability to tolerate grazing - grasses have very low growing points - grasses have very low growing points - also have rhizomes - also have rhizomes - plantain/dandelion have a rosette habit – leaves pressed against ground - plantain/dandelion have a rosette habit – leaves pressed against ground - many plants have enormous powers of regeneration - many plants have enormous powers of regeneration