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what is the short time response to variation?
risk sensitive foraging
what are some long term responses to variation?
- fat storage
what are the sources of variation in energy?
- Availability (seasonality)
- Demand ( lactation or pregnancy)
- both ( winter and night)
what is an example of short term response to variation?
risk sensitive which can be like tossing a coin.
what are some factors associated with risk sensitive foraging?
- Decision: choose to forage in the constant or variable patch
- currency : maximize utility
- constraints : utility function is known, perfect about choices
what does risk sensitivity depend on?
- utility function shape ( indifferent fitness at x means fitness at star)linear
- risk averse ( fitness at x greater then mean fitness )diminishing returns
- risk prone (fitness at x less then mean fitness )accelerating returns
what was the experiment done on bumblees showing that they are risk averse?
they foraged on 40 flowers. there where blue with constant and yellow which had different concentration. the experiment showed that they tend to go toward the one offering the most price
what factor does utility depend on?
it depends on energy stores
what is torpor and what kind of animals do it?
- it is reduction in body temperature and elephant shrews and some species of bats do it. torpor saves energy
- In an experiment it was shown that oxygen consumption of active bats increase with decreasing the air temperature . so oxygen consumption measures energy use and energy use increases as ambient temperature decreases
what benefits does fat have as energy storage?
- it is a light molecule and can be metabolize quickly and it is energy rich.
- animals lay fat when they experience unpredictable environment and reduce it when in constant environment.
- fat is not free , it can increase predation rate and decrease locomotion.
what animals cache food?
spiders, ants, bees and wasps are arthropods and rodents , pika hawks and jays are vertebrates that cache food.
what are some reason that animals cache food instead of storing fat?
- fat increases risk of predation because it increases body mass
- not all can store fat if food is abundant
- large stores provide food supply for group over winter
- easily transferable to offsprings
what is animal agriculture associated with?
It provides constant food source despite changing environment.