BISC495: Habitat Selection & Dispersal Vocabulary

Habitat Selection

the process by which organisms choose where to live based on factrs affecting fitness

Ideal Free Distribution (IFD)

theory stating that individuals distribute themselves among habitats proportional to available resources

Territory

an area actively defended against others

Home Range

area regularly used by an animal but not defended

Territoriality

behavior involving defense or space/resources

Site Fidelity

returning repeatedly to the same territory or breeding site

Innate Behavior

behavior genetically programmed/inherited

Learned Behavior

behavior modified through experience

Social Cues

using presence or behavior of other individuals to choose habitat

Dispersal

movement away from birthplace or current habitat

Philopatry

returning to or remaning near birthplace

Inbreeding

mating between close relatives

Inbreeding Depression

reudced fitness caused by breeding with relatives

Outbreeding Depression

reduced fitness caused by mating with individuals too genetically different

Natal Dispersal

movement away from birthplace before reproduction

Sex-Biased Dispersal

when one sex disperses farther than the other

Energy Trade-Off Hypothesis

energy used for one function cannot be used for another (ex: flight vs. reproduction in crickets)

Anadromous

fish migrate from ocean to freshwater to breed (ex: salmon)

Catadromous

fish migrate from freshwater to ocean to breed (ex: eels)

Seasonal Exploitation Hypthesis

migration evolves to exploit seasonally changing resources