Social Groupings

Question 1

What is a hierarchy

Answer 1

A system in which members of a group are ranked according to status or authority
Highest ranking=dominant
Lowest ranking=subordinates

Question 2

How are hierarchies formed

Answer 2

~In the early stages, animals will fight for dominance and test the strength of their challenger
~Animals soon learn that there are some individuals they should not bother challenging, as the other animal will win
~As this goes on, the stronger animals become dominant, and the weaker become subordinate

Question 3

Case study: schjelderup-ebbe 1935

Answer 3

~Observed hierarchy in hens
~Watched behaviour of hens and noticed that one gradually became dominant and was in charge of the others
~below her was a second ranking bird, dominating over all but the top hen.
~this continued down the line, with the bottom ranking bird being superior to none
~this is a linear hierarchy.

Question 4

What is a linear hierarchy

Answer 4

~linear hierarchies are in a clear order
~complex hierarchies can be triangular eg if there was 3 individuals, a could dominate b with be dominating c.
~there is always one individual in charge

Question 5

Pros of hierarchies

Answer 5

Pros
~dominant animals are prioritised where feeding and mating, etc are concerned
~individuals in a group are often related, so subordinates may share genes with dominant animals
~animals can avoid having to fight others regularly, as they recognise those that are likely to win
~living in a social group with a strong, dominant presence can offer some protection for subordinates

Question 6

Cons of a hierarchy

Answer 6

Subordinates
~may eat last, less/lower quality food
~mating can sometimes be suppressed

Dominant animals
~can be challenged if they show weakness
~make them a target
~changes in group dynamics/structure can lead to them being displaced or even killed

Question 7

Hierarchical changes

Answer 7

~dominant animals becoming less strong with age
~subordinates challenging dominant animals successfully
~weakness shown by dominant animal or strength shown by subordinate
~changes to group dynamics, through introduction of new animals
~maturing of juveniles into dominant adults
~changes to territory
~injury or illness shown in dominant animals
~changes to status badges eg a male lion losing how mane may also lose dominance

Question 8

What is agonistic behaviour

Answer 8

"Any social behaviour related to fighting"
Why do animals show this 
~Defend territory 
~hunting 
~establish dominance 
~intimidate competitors/predators