DISADVANTAGES OF GROUPING

Question 1

What are the disadvantages of group living?

Answer 1

1. Increased conspicuousness to predators
2. Competition in feeding
3. Disease transmission
4. Cuckoldry and mate competition
5. Cannibalism of young

Question 2

1. increased conspicuousness to predators

Answer 2

Colony of fieldfare nests attracts more predators than individual, however they have protection from mobbing so benefits outweigh cost

Question 3

2. Competition in feeding- direct exploitation

Answer 3

e.g. in predatory fish hunting in a school- fish at front catch more than in back

Question 4

interference between group members

Answer 4

redshank feed on shrimps that retreat into burrows when they detect an approaching bird. neighbours may disturb each others prey

Question 5

3. Disease transmission

Answer 5

cliff nesting swallows build nests close this facilitates transmission of blood sucking swallow bugs

Question 6

4. Cuckoldry and mate competition

Answer 6

in colonial nesting red-winged blackbirds the mates of vasectomised males laid fertilised eggs indicating that they had been fertilised by a male other than the mate

Question 7

5. Cannibalism of young

Answer 7

Bluegill sunfish have nests close together. A male may eat his neighbours eggs.

Question 8

Ideal group size

Answer 8

In which the fitness of an individual is maximised. Reflect a balance between various costs and benefits. time spent in vigilance and fighting combined is lowest.