lecture 17 - foraging Flashcards
what is search image theory
theory that animals form representation of their food that becomes more detailed with experience
what is optimal foraging theory
a theoretical framework that allows researchers to predict various aspects of foraging behavior within constraints
how do OFTs range
from very simple to very complicated depending on # of variables included
what is the baseline of OFt
set of assumptions about the animal
what does OFt calculate given contraints
which food types a forager should take
how does OFT predict what to eat
in the simplest possible case you just choose between 2 food types. here the encounter rate of the more profitable item dictates whether the less profitable item is included in the diet. the encounter rate of the less profitable item has no impact on its inlclusion
how can you calculate profitability of a prey-food item
energy value (calories provided to forager) / handling time (time to kill and inject)
how does OFt predict where to eat
forager should stay in patch as long as the reduced food availability does not justify move to the next patch (bc traveling is costly). the greater the time between patches, the longer the forager should stay in a patch
what does the marginal value theorem model calculate
the trade off between traveling cost and the cost of staying in the same patch
how does OFT predict specific nutrient constraints
use models to determine trade off between foraging for energy rich plants and other plants that will help them get nutrients but don’t have as much energy
how do moose balance getting salt and more energy plants
spend more time on lakes during summer to store the salt necessary for winter survival
how do OFT predict risk sensitive foraging
when food isn’t spread evenly in an environment (so you can risk not finding anything) then if the hunger state of the forager is taken into account, starving animals will take the risk more than other animals
how does increasing group size affect foraging
increases amount of food received and reduced amount of time needed to spend on antipredator activities
what is the critical group size for bluegill sunfish foraging
4
what are producers
find and produce food
