Eating and Surviving

Question 1

What situations does MVT apply to

Answer 1

1) An animal exploits a discrete site/patch
2) Within a patch, returns decrease over time (asymptotic (diminishing) gain curve)
3) There is a cost in getting to / from the patch

Question 2

In MVT what happens when travel time is lower

Answer 2

Both search time and the load are lower

to maximise Rate

Question 3

In terms of foraging, what does the MVT tell us

Answer 3

It tells us how to optimise rate gain

Question 4

Benefits to living in groups

Answer 4

• Anti-predation
• Inter-specific competition
• Thermal advantage
• Mobility advantage
• Foraging efficiency

Question 5

Costs to living in groups

Answer 5

• Competition
• Interference
• Cuckoldry
• Cannibalism/infanticide
• Parasites

Question 6

What is the benefit of sharing vigilance load

Answer 6

Don’t have to spend so much time looking out for predators, instead you can be eating

Question 7

What does the economics of defendability depend on

Answer 7

vary depending on shape of cost and benefit relative relationships and the quality of the resource

Question 8

Why does increased predation risk lead to larger flock size

Answer 8

If there are more predators. then there will be more scanning required, which reduces each individuals feeding time. Therefore to optimise feeding rate flock size will increase to decrease the amount of time each individual will spend scanning

Question 9

Example of antipredator defences (not flocking)

Answer 9

Crypsis - stick insects
Diversion - Shanghai skink undergos costly autotomy to escape being eaten
Distaste - skunks and bloody-nosed beetle releasing hemolymph
Armour - tortoises
Distraction - squid and octopuses inking
Aggression - Malaysian exploding ant suicidally expels the contents of its hypertrophied submandibular glands,[