Lecture 13- Animal collectives I

Question 1

6 advantages of collective behaviour

Answer 1

anti-predator defence
enhanced thermoregulation
locomotion advantages
social support
cooperatice care of young
improved foraging/hunting
information sharing

Question 2

example- predation avoidance

Answer 2

took a lot longer for lizards to strike when presented with 20 worms rather than 1, also more fixation events suggesting more difficulty hunting

Question 3

example of social thermoregulation

Answer 3

bats- higher temperatures (min and max) with higher group number, saving of about 50% of daily energy budget in largest groups

Question 4

example of enhanced locomotion

Answer 4

birds- air being pushed around, helps other birds ‘coast’ and save energy

Question 5

social support- example

Answer 5

monkeys- higher infant survival where there is higher sociality index

Question 6

3 costs of collectives

Answer 6

disease, increased energy demands
higher stress level
increased competition

Question 7

factors involved in the ecological constraints model

Answer 7

ecological maximum group sizes, beneficial minimum, and cognitive max for a specific factor (such as rainfall)

Question 8

example of a factor which can contribute to group size changing

Answer 8

food availability- larger subgroups when there is more food abailable

Question 9

why are intermediate group sizes good

Answer 9

least travelling (less displacement/needing to move to meet demands), least stress due to competition

Question 10

factors which can influence leadership

Answer 10

age/experience, being informed, dominance, speed, motivation- e.g. ant cheerio example, changing leader with knowledge, or pigeons picking a leader based exclusively on speed, orcas and post-reproductive female leadership

Question 11

‘grandma hypothesis’

Answer 11

idea that it becomes more beneficial to invest in helping kin after reproduction