Coping With DangersCoping With DangersChapter 26Chapter 26

Avoidance Behaviour & Avoidance Behaviour & HabituationHabituation• Avoidance behaviour is an escape Avoidance behaviour is an escape

response – unlearned behaviourresponse – unlearned behaviour• E.g. snail retreats into it’s shell if tappedE.g. snail retreats into it’s shell if tapped• - eventually snail doesn’t react- eventually snail doesn’t react• This is learned behaviour – This is learned behaviour – habituationhabituation• Habituation is short livedHabituation is short lived• Animals can be motivated to respond to Animals can be motivated to respond to

a stimulusa stimulus

Learning ExperimentsLearning Experiments• Humans can improve their performance in Humans can improve their performance in

basic tasks through practicebasic tasks through practice• Eventually a maximum performance will be Eventually a maximum performance will be

reachedreached• This can be represented on a This can be represented on a learning curvelearning curve• Learning can often provide a long-term Learning can often provide a long-term

modification of behaviourmodification of behaviour• Depends upon animal being capable of Depends upon animal being capable of

rememberingremembering

Learning to avoid dangerLearning to avoid danger• ToadsToads• - will snap at any insects- will snap at any insects• - if it snaps at a bee and gets stung, it avoids - if it snaps at a bee and gets stung, it avoids

striped insectsstriped insects• BirdsBirds• - Hatched ducks/goslings follow first large object - Hatched ducks/goslings follow first large object

that moves and makes soundsthat moves and makes sounds• - this is normally in response to mother- this is normally in response to mother• - this early life experience is - this early life experience is imprintingimprinting• - has a significant survival value- has a significant survival value• HumansHumans• - 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 Intelligence, and use of reasoning, affects ability of

animal to learnanimal to learn

Individual mechanisms of Individual mechanisms of defencedefence• ActiveActive• - 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• PassivePassive• - 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 - colouration & poisonous chemicals – e.g. kokoi

frogfrog• - 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 - butterfly fish has deflection displaydeflection display

Social mechanisms for Social mechanisms for defencedefence• Many species rely on ‘safety in numbers’Many species rely on ‘safety in numbers’• E.g. schools of fish, herds of mammals, flocks of birdsE.g. schools of fish, herds of mammals, flocks of birds• Musk OxMusk Ox• - no hiding places (barren environment)- no hiding places (barren environment)• - under threat, form a protective group – this is - under threat, form a protective group – this is

mobbingmobbing• QuailQuail• - Roost in circles – heads facing outwards- Roost in circles – heads facing outwards• - ‘explode’ into predators face- ‘explode’ into predators face• BaboonBaboon• - 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 plantsDefence in plants• StructuralStructural• - 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 grazingAbility 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 - plantain/dandelion have a rosette habit – leaves

pressed against groundpressed against ground• - many plants have enormous powers of - many plants have enormous powers of

regenerationregeneration