aggression and play Flashcards
what is aggression
a defensive posture or attack either through threat or competition, it is based on intention - predation is not aggression
give some reasons for aggression
defence
courtship/ reproduction
resource competition - inter or intraspecific
territoriality
dominance
what are some different ways of signalling aggression
1) olfactory signals e.g. stink fights in ring-tailed lemurs
2) auditory e.g. call may reflect size or status of caller
give an example of a species which uses several signals
red deer in rutting ise
visual - antlers
auditory- roaring
olfactory- preorbital gland secretions
give an example of a species which uses aggression in reproduction
male Hamadryas baboons bully young females into staying in the harem and use coercion of females to reproduce
give an example of a species which uses aggression in parental care
adult moorhens can be aggressive to chicks which reduces sibling rivalry and encourages independence
what is kelptoparasitism
parasitism by theft - a form of resource acquisition where one animal takes resources from another
what are the ‘laws of battle’ in regards to intra-specific competition
1) natural selection would favour animals that compete successfully
2) direct fighting is most common form of competition
3) fights in nature rarely occur as they can cause injury so animals avoid unrestrained battles
THE GREATER THE REWARD THE GREATER THE DEGREE FO TOLERATED POTENTIAL DAMAGE
what is ritualised fighting in regards to intraspecific competition
- most fights are restrained so avoid using most powerful weaponry
- often proceed through several stages with opposition dropping out at any time
what is meant by a dominance hierarchy and social conflict
common but not universal in social group organisations
occurs between relationships between group members with dominants having priority over subordinates e.g. over food, mates and resources
what decides dominates
e.g.
hens = larger size and more testosterone
parasites affect dominance in mice
sex influences
outline some characteristics which are seen in dominance hierarchies in primates
very complex
some form alliances between individuals
status determined in short term temporally by conspecifics
who wins more in a fight, individual living in that territory or the individual trying to take over
owners are often stronger as territory owners tend to have more to lose so are prepared to fight harder, they also have a more in depth knowledge of the territory
how can social groups have conflict over space or resources
e.g. kidnapping ants, several species raid opposing nets and bring offspring back to their nest and use them as slaves after emergence
how is mobbing used as a defence in birds
when a predator is discovered the birds start to emit an alarm call and fly at the predator diverting attention and harassing it, sometimes even making physical contact
