Feeding and foraging

Question 1

What type of analysis of foraging behaviour can be conducted?

Answer 1

Cost/behefit analysis and economic

Question 2

What is the general theory of foraging behaviour?

Answer 2

Relative profitability of food item decreases as searching/handling time increases - input energy too great cf. energy gained from it
eg. crabs eating mussels - tend to eat medium sized ones

Question 3

How can foraging behaviour be appiled practically?

Answer 3

• Grass length on airstrips - bird strike common. If grass left to grow foraging is too costly and they will forage elsewhere
• Starlings raiding farm food supplies - grind instead of roll oats, increases effort of eating, decreases profitability

Question 4

What is the central place foraging theory?

Answer 4

eg. Bullfinches make forays into orchards from adjacent woodland (cover) - Damage of edge trees. Small amounts of damage to each tree not economically costly, but loss of outer trees is.
- Short flights are not cost effective
- if all trees are far away from shelter then they are equally likely to be visited [damage is spread,] if they are close then the closest tree is most likely to be visited.

Question 5

Who investigated the central place foraging theory?

Answer 5

Greig-Smith 1987 - Bullfinches and orchards

Question 6

What did Sullivan and Sullivan 1982 investigate?

Answer 6

Deer mice taking pine plantation seeds - if sunflower seeds scattered (easily available) will preferentially take these and leave pine.

Question 7

What is the Garcia effect?

Answer 7

Conditioned aversion learning

Stimulus and response do not have to be close in time (contingency not necessary)

Question 8

Give an example of the Garcia effect used practically?

Answer 8

Methiocarb + crop -> short illness
Crop -> Avoidance
- used in USA redwing blackbirds

Question 9

How may stimuli be altered to improve learning about them? Why may this be useful?

Answer 9

Avery and Mason 1997

• Make them more salient or surprising, or add multiple components to stimulus
• eg. adding colour to rice alongside illness inducing (methiocarb) substance gives same avoidance as adding irritant (methyl anthraniatate)
• combination of all 3 gives greatest avoidance

Question 10

Who else investigated addition of colour to increase aversion?

Answer 10

Greig-Smith 1990

Question 11

Who demonstrated generalisation of food aversion?

Answer 11

Avery 1989

- 0% v 50% v 100% methiocarb on sown rice plots

Question 12

How does social learning affect feeding and foraging?

Answer 12

Galef and Wigmore 1983 - naive rats exposed to demonstrator who has eaten novel food (coco or cinnamon)
- Naive rats choose demonstrators diet preferentially

Question 13

How does aversion learning interact with social learning?

Answer 13

Galef 1986 - Naive rat exposed to demonstrator, but then allowed to eat both foods in succession

• then vomiting induced (LiCl) - USUALLY makes them avoid novel food
• will still choose conspecific food
• even if conspecific anaesthetised

Question 14

What signal may be required concurrently with food smell to encourage eating?

Answer 14

Carbon disulphide - biproduct of digestion

> adding to baited traps could increase intake and efficiency