Ecology: Biogeography and Behavioral Ecology

Definition of biogeography

The scientific study of variation in species composition and diversity at geographic scales

Definition of alpha (α) diversity

Local species richness (the number of species in a sample); looks at the single community being studied with no other comparisons

Definition of beta (β) diversity

Change in species composition from one site to another (species turnover); compares species composition of the studied site and one nearby

Definition of gamma (γ) diversity

Regional species richness; looks at communities further apart

Do smaller or larger islands have higher immigration and why?

Immigration is higher for larger islands because it’s easier to find larger islands than smaller ones

Island size controls what?

Island size controls extinction rates (smaller islands have higher rates of extinction)

Island distance controls what?

Distance from the mainland controls immigration rates (nearer island has higher immigration rates)

What are different methods of dispersal of terrestrial animals?

Corridors, filters, sweepstakes route

Definition of corridor

A route that nearly all members of a taxon can easily traverse; must be relatively easy to move through

Definition of filter

Acts like a corridor, but species can be stopped, are able to cross, or can cross once and cannot recross at a later time

Definition of sweepstakes route

Very few species made it to a certain habitat, and when they get there, they “win big” and are able to survive and thrive

Example of a sweepstakes route

Lemurs getting to Madagascar

Definition of monogamy

One of each sex is involved (1 male, 1 female), species are often cooperative and solitary

Definition of harem polygyny

One male and more than one female are involved

Definition of polyandry

One female and more than one male are involved, involvement can be serial or simultaneous

Examples of species involving multiple individuals (more than one male and female)

Multi-male polygyny, promiscuity, polygynandry (coop, egg-laying)

Definition of proximate causes

What mechanism enables the organism to exhibit the behavior; what’s going on at the moment

Definition of ultimate causes

What was happening over an organism’s evolutionary history that led to a certain behavior

Definition of altruism

An organism risking its own genetic fitness to help another organism out of a life-or-death situation