Island Biogeography – Vocabulary Flashcards

Flashcards focusing on vocabulary terms and definitions from the island biogeography notes.

Island biogeography

The study of ecological relationships and distribution of organisms on islands and of their community structures, including how island size and distance influence the number of species.

Habitat island

A patch of suitable habitat surrounded by a different, usually unsuitable habitat (e.g., a park) that functions as an island for species.

Immigration rate

The rate at which new species colonize an island; highest when the island has no species and declines as species accumulate; increases with proximity to the mainland.

Extinction rate

The rate at which species on the island go extinct; tends to be low when populations are large and increases as populations shrink and more species arrive.

Equilibrium number of species (S-hat)

The steady-state number of species on an island where immigration and extinction rates balance.

Island size (area)

The total area of the island; larger islands support more species, more niches, more resources, and lower extinction rates.

Distance from mainland

The distance from the island to the nearest mainland; greater distance lowers immigration and reduces the equilibrium number of species.

MacArthur and Wilson

Ecologists who developed the theory of island biogeography, linking immigration, extinction, island size, and distance to explain species richness.

Darwin’s Finches

A classic example of island biogeography influencing evolution; isolation and island-specific pressures led to diversification and adaptation.

Specialists vs Generalists

On islands, species often become specialists due to limited resources; invasive generalists can outcompete specialists, threatening their long-term survival.