Living In Groups

Question 1

Anti predator benefits of living in groups:

Answer 1

• vigilance
• risk dilution (safety in numbers) due to predator avoidance and attack dilution
• predator confusion (can overwhelm predators sensory abilities using synchronised behaviours
• communal defence (fight back against e.g. radial formations in elephants)
• abatement (predators avoid large groups)

Question 2

Do all group members benefit equally?

Answer 2

• phenotypic heterogeneity - e.g. confusion effect maximal if all individuals look same, odd individuals are singled out by predators
• positional heterogeneity - peripheral positions in herd are more risky = jostling for central positions

Question 3

Foraging benefits of group living -

Answer 3

• Increased vigilance = increased foraging time
• improved food location (increased search area per unit of time) = find food faster
• improved chance of catching prey
• organisation and role specialisation during group hunting = easier to catchy prey

Question 4

Anti parasite benefits of group living:

Answer 4

• parasites are limited to selecting a single host at a time
• groups provide dilution effect

Question 5

Mating benefits of living in groups:

Answer 5

• access to and assessment of a large number of potential mates
• leks = Male courtship display areas - allow females to compare multiple males

Question 6

Energetic benefits of living in groups -

Answer 6

• thermal benefits (e.g. penguins)

Question 7

Potential costs of group living:

Answer 7

• foraging costs (competition, steeling of resources, interference, aggression, prey may spot large group mor easily)
• antipredator costs (predators may spot large groups easily)
• increased pathogen transfer