Intraspecific Relationships

Interaction between members of the same group

Competition

More intense than interspecific competition For the same resources eg

Food Water Space Home sites Shelter Light, etc

As members of the same species have the same needs, their competition is the strongest

Group Interactions

Interactions can also be co-operative Courtship Pair-bond formation Caring for the young

Interactions here can be competitive Looking for a mate Looking for a home site

Co-operative Interactions

Quite often found in Group formation Pair-bond formation Parental care

Group formation

Advantages Hunting Defence Protection Insect societies Clumping Confusion Breeding

Disadvantages Competition Disease and parasites Increased conflict

Pair-bond formation

A pair bond is a stable relationship between animals of the opposite sex that ensures co-operative behaviour in mating and the rearing of the young

Parental Care

This has a large effect on the complexity of animal behaviour

Most species tend to fit into either r strategies k strategies

r Strategists

Produce large numbers of gametes Fertilised eggs then left to own devices Very few survive but these must maintain the

population Parentla care is avoided saving resources

and energy for survival Mating must be co-ordinated and successful Eg:

Simpler invertebrates Most fish, amphibians and reptiles

k Strategists

Deliberate parental care Change of survival much higher for each fertilised

egg so less gametes produced Gain in energy conservation from less gametes

production is offset by extra expenditure on group interactions and/or effort in parental care

May be basically solitary as adults with parental care being left to either mother (mammals) or father (emu, ostrich)

The different reproductive strategies

Monogamy Polygyny Polygamy Polyandry Polygynadry (promiscuity) Synchronised spawning Co-operative breeding Kin selection Social insects

Aggressive Interactions

Aggressiveness is a mood It arises form competition Fear is an important part of aggression Fighting is ritualised with the moves known to both

opponents, thus allowing a winner and loser without serious injury

Fighting to the death does not occur very often and is usually to eliminate a stranger

The winner ends up with the greater share of the resource meaning they are more likely to survive and pass on their genes

Territories

Organisms do not usually crowd together Each is surrounding by a personal space The home range is an area the animal

seldom leaves The territory is the area an animal will mark

and defend Animals hold territory through aggressive

behaviour

Hieracrchies

Animals tend to organise themselves into an order of dominance (pecking order)

Usually achieved through aggressive interactions

Once established the competition in the group usually diminishes