lecture 12 Flashcards
migration
seasonal movement from one type of habitat to another
round-trip
ex: humpback whale migration
pigeon navigation capabilities
- visual (sun-position)
- magnetic (granules in brain)
- olfactory
warbler navigation capabilities
- visual (night sky star pattern)
- north-south orientation
navigation
when an animal uses distinct clues to determine its position as it attempts to reach its goal
steelhead trout navigation capabilities
oflactory (sniff out natal stream to breed and olfactory maps)
emigration
an animal departs out from an area to a new area without returning
one-way
reasons for emigration
- optimal breeding (outbreeding)
- search for a better environment
- deteriorating environment
- overpopulated environments
female philopatry
females stay in their natal area
male philopatry
males stay in the natal area
realized niche
niche that is less desirable but due to competition has been forced into occupying
ex: coho and chinook salmon
negative taxis
movement away from a stimulus
postitive taxis
movement towards a stimulus
orthokinesis
an organism changes its speed in relation to intensity of a stimulus
ex: pill bugs
klinokinesis
a change in an organisms turning rate in reaction to intensity of a stimulus
ex: lamprey fish
abiotic population regulators
cyclones, fire, volcanic eruptions
biotic population regulators
parasitic infections, prey populations, predator populations
role of keystone species
if removed they have a dramatic effect on the population of other animal species that interface directly and indirectly with them
torpor
short-term reduction of internal body temperature during cool day/nights
can be caused by low food availability or cool temperatures
ex: hummingbirds
hibernation
extended and protracted torpor caused by reduced daylight length and hormonal changes
body temps plunge lower than torpor
ex: artic ground squirrels
