Environmental Adaptations Flashcards
Endotherms use enzymes with optimal temp between _____
38 -42C
benefits of endotherms
independence from temp extremes
can extend activity periods of 24h
colonize many envr and ecological niches
better at catching and escaping prey
methods to staying about 0C
behaviour - migration
physiological - adjust Tb
morphological - smaller appendages
-get big
how to reduce heat loss (5)
get big allen's rule adjust MBR insulation lower conductive heat loss restrict evaporative heat loss
an arctic fox’s decrease in appendage size are an example of what rule?
allen’s rule
decrease size of extremities
insulation of the arctic fur’s hair is increased by (3)
increased density
structure of hair
thickness of fur
why are many arctic animals white?
lack of melanin in animal fur leaves more space for cavities = better insulator
might reflect light onto black skin
is blubber more or less insulative than fur?
less - but works well in water
how do reindeer and seals manage energy lost through breathing?
elaborate nasal cavities that increase SA
divide airflow
have thick mucous layer
define torpor
entry of an animal into a hypothermia with behavioural inactivity
define hibernation
sustained state or torpor governed by internal signals and seasonal external cues
when does arousal occur?
if temps go too low
spontaneously (not good)
some species utilize food caches in winter
what mechanism is used for arousal?
BAT
- brown adipose tissue
- non-shivering thermogenesis
how can animals stay below 40C
reduce activity
seeking cool microclimates
migrating seasonally to cooler climates
how is water economy dealt with?
kidney -papillae -urine can be concentrated diet -metabolic water -oxidized food
how are high temperatures avoided?
find shade
go underground
heat shield
how do kangaroo rats conserve water?
concentrated urine
nearly dry faces
minimize evaporative losses from lungs
venture about ground only at night
remaining in cool, humid burrow during day
How does the Arabian camel cope with extreme heat?
avoidance - thick pelage on upper body keeps heat out -daily body temp fluctuations high body temp in day, lower at night -use cool areas -huddle and seek shade -
how does the arabian camel reduce water loss?
MB water from food or stored fat
reduce water loss ({urine} and dry feces
store water in hump as fat
