Ch. 24 - Dispersal Flashcards
This is movement from a point of origin to an area where reproduction occurs
Dispersion
Is spatial distribution typically uniform, random, or clumped?
Clumped
Why does spatial distribution tend to be clumped?
Resources tend to be clumped
What are the three types of temporal distribution?
Immigration, emigration, migration
What are three types of daily temporal distribution?
Diurnal, nocturnal, and crepuscular
What are the two types of dispersal?
Passive and active
Plants and insects commonly use this type of dispersal
Passive dispersal
What are four vectors of passive dispersal?
Wind, gravity, water, animals
Mammals and birds use this type of dispersal
Active dispersal
This is the dispersal of young
Natal dispersal
This leads to aggression between older/younger individuals or individuals within the same sex
Social dispersal
Social dispersal is common in this group of mammals
Rodents
This is the return to the place of birth for breeding
Philopatry
These are dispersal/migratory routes that offer little resistance
Corridors
Corridors allow this in ecosystems
Ecological connectivity
These allow the dispersal/migration of certain animals and stop others
Filters
What are four examples of dispersal filters?
Mountain ranges, deserts, tropics, land bridges
What are five benefits of dispersal?
- Reduces inbreeding; 2. Expansion into new habitat; 3. Repopulation of extirpated areas; 4. Enabling sink populations; 5. Reduces intraspecific conflict
What are two risks of dispersal?
- Inherent dispersal/migratory risks; 2. Potentially populating less suitable habitat
This is large-scale movement across habitat types that may or may not require a return trip
Migration
What are four examples of mammals that migrate?
Bats, ungulates, whales, pinnipeds
What are three things that migration results from?
- Evolution adaptation; 2. Environmental adaptation; 3. Selective pressure
What is an evolutionary advantage of migration?
Access to multiple habitats
What are two selective pressures that lead to migration?
Predation and social pressures