lecture 3- chap 2.docx

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18 Apr 2012
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9/21/2011 6:55:00 AM
- dead air trapped in fur is what insulates animals. Birds can puff up
when they want to and slim down when they feel
look for sample test questions to do well on tests. Lookon portal for the
past question
Lecture 3
Slide 1
- some cases where
-weasels are long and skinny. they loose heat very quickly. Weasels when
cold cant curl into ball, they curl into circular pizza thing so they loose heat
more than a circular animal.
-the weasels body is well suited to warmer clmate yet they live in mainly
cold climates
- The weasesl body shape isn’t determined by heat regulation, it is
determined by hunting ability. weasels must be thin in order to get theyre
prey inside of the ground. Essentially it is a trade off where it gets hunting
ability but trades off thermo regulation.If the weasel is a good hunter, they
can get a lot of food and that provides neccasary calories for both hunting
and thermoregulation
two reasons why natural selection creates imperfect organisms
1) tradeoffs- get one thing while sacrificing another
2)constraints- selection builds on whats already there. Tinkering occurs but
brand new design doesn’t occur
Kangaroo rat(dealing with extreme water stress)
-the water rat lives in a very dry environment
- to deal with lack of water, it does the follwong
a) anatomy: rerect, off of ground and ther is less ytransfer of heat from
ground to body (convection)
b) physiology: supper efficient kidneys produce very concentrated pee. Still
needs water and it gets it from metabolic water. Metabolic water is water
which comes from seeds which naturally have water in it, and they get it
from the fat in the seeds. When fat is broken down water is created
c) Behavior
- nocturnal; spends hot days underground
- collect seeds underground. They cache the seeds underground. When they
go to sleep, the seeds which they are near when they sleep absorb the
moisture from their breaths and when they eat the seeds they get back the
When there is to much stress- Evasion
-enter dormant stage
- migrate to milder climate
-hibernation as adult. Stores fat
-enter nest
- birds will for the most part go to migrate and hibernate to wait for food to
be ripe .
-migratory birds will migrate for food supplies, not for temp
Masters of evation
- garter snakes will sleep together to conserve heat
- chipmunks will go through large physiological shift. Heart rate… slows
down and fattening in fall serves them through winter
-muscrats make dome like house, which provides space over winter they can
be protexted from predators and cold.
Winters in moutians: migrnars versus residents
- birds with nothing to eat migrate to southern altitudes
- cross bill birds can feed on seeds in cones of spruce and other trees. They
have gaurenteed food supply. If an animal can get enough food, it can stay
- grey jays scavange for food dropped. They will eat anything
Macking Hay
Clarkes nutcracker:
- stores nuts in pouch
- live in crevices of rocks, not hibernator, need food to make it
- make hay piles which they dry out in the summer and then store it and
eat it in the winter
Conclusions for physiological ecology
- not just physiology
-behavior is essential component
- adatations work together in coordinated ways