L12 - Group Living

Question 1

What are the benefits associated with group-living?

Answer 1

Increasing you ability to find food

Decreased likelihood of predation

Question 2

What are the costs associated with group-living?

Answer 2

1) Competition
2) Disease risk
3) Risk of being cuckolded - unfaithful partners
4) Risk of being cannibalised - parents leave for a time and offspring can be cannibalised boy others
5) Inbreeding

Question 3

How do the costs & benefits of group-living differ among individuals?

Answer 3

Not all individuals benefits from group living:

• Central herd positions taken by larger/dominant individuals, means smaller weaker ones are more at risk of predation
• Reproductive females are kept in the centre
• hungry individuals at the edge

Question 4

When should animals join a group?

Answer 4

Only when it is a net benefit to them - individual factors - influences group size

Question 5

How do group-living animals make decisions?

Answer 5

1) Go with the majority - like in bees

2) Follow a leader

Question 6

What is niche expansion?

Answer 6

Larger groups can take down bigger prey

Question 7

Why should animals join a group?

Answer 7

More physically protected

More camouflage from others

More eyes for seeing predators

Increased foraging time

Information centres from other more knowledgeable animals

Niche expansion

Question 8

What is the confusion effect?

Answer 8

A large moving group makes it much more difficult for a predator to target an individual

Question 9

What is the oddity effect?

Answer 9

An individual that is the ‘odd one out’ in a group visually, is more likely to be targeted - removes odd phenotypes

Question 10

How is feeding time increased by living in a group?

Answer 10

1) Increased time foraging as other eyes are looking for predators
2) Depletion avoidance: groups can reduce the likelihood of encountering depleted patches
3) Information centres