survival value

Question 1

2 ways of studying the survival value of behaviour

Answer 1

1. comparative

2. experimental

Question 2

comparative method

Answer 2

Compare the behaviours and habitats of related species. Suggest survival values of behaviours in the habitats in which they occur.

Question 3

experimental method

Answer 3

Experimentally manipulate the consequences of behaviour or other traits. Measure effects on survivorship and/or reproductive success

Question 4

pros of comparative studies

Answer 4

observing natural behaviours in different habitats can provide useful insights and generate hypotheses that can be tested

Question 5

cons of comparative studies

Answer 5

where alternative alternative interpretations exist, it can be hard to test which one is correct

Question 6

conclusions to tinbergen egg shell experiment

Answer 6

• Egg shell removal saves unhatched eggs

- There is selection pressure for parents to remove broken egg shells

Question 7

tinbergen experiment

Answer 7

Tinbergen laid out eggs 20 m apart on land adjacent to a black-headed gull colony. Some eggs had broken egg shell beside them, other not
Predators (carrion crows) appeared and ate some of the eggs
Those with broken egg shell beside them were taken earlier

test the hypothesis that egg shell removal improves the camouflage of the nest and so improves the survival of unhatched eggs and chicks.

Question 8

light and pale skin in sun

Answer 8

• weak sun: pale skin facilitates production of vitamin D from ultraviolet radiation
• strong sun: dark skin protects against UV radiation and cancer

Question 9

cullen’s experiment

Answer 9

• compared behaviour of ground- nesting gulls (herring gulls) and cliff- nesting gulls (kittiwake gulls)

Question 10

conclusion of cullen’s experiment

Answer 10

behaviours are genetically determined and have survival value in the environments in which they occur. The suggestion is that all the kittiwake behaviours have evolved since the time when its ancestor was a ground-nesting gull.

Question 11

andersson’s survival value experiment conclusion

Answer 11

males with lengthened tails had higher reproductive success as measured by the numbers of nests in male territories
Male behaviour did not appear to be affected.

Question 12

andersson’s experiment

Answer 12

He recorded the number of females in the territory of each male and then divided the males into four groups:-

1. Shortened tails (25 cm removed)
2. Control I (cut and glue)
3. Control II (just ringed)
4. Lengthened tails (25 cm added)

Tail length was manipulated using scissors and superglue