chapter 11: foraging

Question 1

foraging

Answer 1

searching for an consuming food

Question 2

search image

Answer 2

forming a representation of a prey item so it becomes easier to find over time

Question 3

optimal foraging theory

Answer 3

a set of mathematical models used to predict various aspects of animal foraging behavior within a given set of constraints

Question 4

what are the advantages of search image?

Answer 4

helps and animal filter out what is and isn’t prey, response to finding cryptic prey

Question 5

what are the 3 categories of OFT models we talked about-

Answer 5

1. what to eat
2. how long
3. how does variance impact what is eaten

Question 6

what does each prey item have?

Answer 6

• energy (e)
• encounter rate (lamda)
• handling time (h)

Question 7

energy value

Answer 7

e, how much energy it provides the animal eating it

Question 8

encounter rate

Answer 8

lamda, how often the animal eating it encounters it

Question 9

handling time

Answer 9

h, how much time it takes for an animal to find, kill and ingest the prey

Question 10

what is the profitability formula

Answer 10

p= e/h

Question 11

what does the OFT model predict about which type of prey should be chosen during foraging?

Answer 11

weighs the costs and benefits to predict what an animal should do to maximize its fitness

Question 12

if given a choice between 2 prey items an one is more profitable than the other, what does the OFT model predict about when to eat the less profitable prey? what variable matters the most?

Answer 12

• NEVER IGNORE the prey 1, if ODM is true then you should ONLY take the most profitable, but if it is false you should take both
• the variable that matters the most is lamda 1 also known as encounter rate of prey 1

Question 13

what are the main points of the great tit study?

Answer 13

great tit (bird)
- presented with big and large food
- increase intake of small food as encounter rate for big food goes down

Question 14

what does the OFT model predict about how long an animal should remain in the same food patch that is being depleted over time?

Answer 14

it predicts that
- food depletion
- potential predation during travel
- lost time foraging

Question 15

what is the Marginal Value Theorem?

Answer 15

a model used to predict how long an animal should remain in the same patch

Question 16

what are the MVT predictions?

Answer 16

gains of staying in a patch will decrease as a patch is depleted by a forager

Question 17

know how to read a gain curve

Answer 17

x axis: time
y axix: energy gain or food intake
overall: arrive time where the curve starts on x axis and then as time goes on, the gain increases and then flatens out and plateaus

Question 18

when should a forager stay in a patch?

Answer 18

they should stay in a patch until they can do better elsewhere

Question 19

when should a forager leave?

Answer 19

• when the gain curve flattens
• at the point when the line touches the curve is the optimal time to leave

Question 20

what ways is the MVT used to understand behavior not related to foraging?

Answer 20

• how long should a male look for a female
• how long should a parasite look for a host

Question 21

what is predicted by the risk- sensitive optimal foraging model?

Answer 21

animal’s hunger state will determine which patch it chooses

Question 22

why does it make sense to be more risk- adverse in consistent food patches and more risk prone in variable food patches?

Answer 22

consistent food patches provide enough energy to meet requirements, and varialbe food patches if you are starving a variable food patch is your best option

Question 23

what are some ways foraging behavior can be affected by group size?

Answer 23

Large groups - can spend less time being vigilant and more time foraging

Question 24

why does increasing gorup size increase the amount of food each forager receives?

Answer 24

the larger the gorup sizw the more eyes there are to watch the group while the others can focus on only foraging

Question 25

What is public information for animals and how can it be used during foraging?

Answer 25

use the actions of others to provide updated information about the eviornment’s condition

Question 26

Understand the results from the “planning for the future” study on scrub jays

Answer 26

the jays stored food in the no food compartment rather than the food compartment to save food for later