Wk 2: Group Living

Question 1

Why do animals live in groups?

Answer 1

• dilution of predation risk
• increased predator detection ability
• increased ability to defend resources
• increased ability to detect & catch food

Question 2

Cooperative behaviour directed towards relatives may evolve through a process called…

Answer 2

Kin Selection

Question 3

What is Reciprocal Altruism?

Answer 3

individuals reciprocate cooperative acts

Question 4

What is Mutualism?

Answer 4

individuals benefit from apparent cooperation

Question 5

What are the routes cooperative behaviour can evolved into?

Answer 5

kin selection
altruism
mutualism

Question 6

Negatives of living within a group

Answer 6

• competition can result in overt & damaging aggression
• increased conspicuousness to predator/prey
• increased risk of disease/parasitism
• competition between group members

Question 7

What mechanisms exist to minimise overt & damaging aggression within groups?

Answer 7

dominance hierarchies
assessment approach

Question 8

Dominance relationship

Answer 8

where one individual has priority of access to resources over another

Question 9

What does a dominance relationship within a group give rise to?

Answer 9

Dominance hierarchy

Question 10

What is an individuals position in the hierarchy refer to as?

Answer 10

Dominance rank

Question 11

Types of hierarchy

Answer 11

Linear and non-linear

Question 12

Downside of hierarchy relationship

Answer 12

Low-ranking individuals may suffer a variety of costs

Question 13

Summary of Dominance Hierarchy

Answer 13

• may be specific to one situation/resource
• low rankers usually incurs more costs
• may exist with minimal aggression once hierarchy is formed (dispute settled on basis of rank)

Question 14

Assessment

Answer 14

the ability of individuals to assess their relative fighting/competitive capabilities and resolve disputes on the basis of their assessment

Question 15

Pros of Assessment

Answer 15

this may allow individuals to assess conflict without overt damage or aggression

Question 16

How is group living flexible?

Answer 16

emigration and immigration can occur when pay-off of living in a group outweigh those of solitary living and vice verse
(individuals cannot defend resources/ when within-group competition is high_

Question 17

With group living be flexible, what can emigration constrain?

Answer 17

acts to constrain over-despotic behaviour by dominants

Question 18

How is flexibility of group living continue in domesticated species?

Answer 18

single and multi-cat household with others (back-yard chickens and pigs) forming groups similar sized to those in their previous species

Question 19

Why is knowledge of the basic principles and concepts of group living useful for animal welfare?

Answer 19

can consider the constraints on group-life caused by captivity, and their implications = animal welfare

Question 20

Some common constraints on group structures/behaviours

Answer 20

• group size, density & composition
• clumped/limited resources
• no voluntary escape options
• rapid enforced (& repeated) mixing of animals

Question 21

Effects pf clumped/limited resources on group living

Answer 21

Low ranking animals may have restricted access to areas if dominants can block key walkways/monopolise clumped resources

Question 22

How may resources be clumped?

Answer 22

Space & Time

Question 23

Consequence of groups of one and who does it effect?

Answer 23

removes benefit of social contact
(dogs, horses & boars)

Question 24

Consequence of very large groups and who does it effecr?

Answer 24

failure to recognise individuals
lack of cooperation/stable hierarchy
(chickens. fish & pigs)

Question 25

Consequence of same-sex or same-age groups and who does effect?

Answer 25

increases similarity in group members; hierarchy less stable
(pigs, dairy calves, chickens)