Island biogeography

Islands in a landscape

Refers to landforms that don't have to be actual islands, but can be any isolated habitat such as mountains, forests, or ponds.

Loss of anti-predator defences

Refers to the reduction or absence of physical and behavioral traits that protect organisms from predators. Example:Dodo.

Loss of dispersal mechanisms

Refers to the absence or reduction of mechanisms that allow the movement of seeds or pollen for reproduction. Often associated with intense specialization and niche formation on islands.

Iceland's lack of endemic species

Due to the relatively short time since colonization, Iceland does not have any species unique to its land.

Equilibrium theory of island biogeography

States that the rate of immigration and extinction of species is influenced by the richness of biodiversity on an island. Closer islands have lower extinction rates and higher immigration rates, while the opposite is true for faraway islands. Island size and location also play a role.

Non-equilibrium effects

Refers to the different rates of colonization and extinction among species based on their dispersal mechanisms. Some species rely on others before they can occupy a new area (stenophagy). Anthropogenic impacts, such as hunting and land-use changes, can also affect non-equilibrium dynamics.

Historical non-equilibrium theories

These theories do not consider the role of evolution in shaping island biogeography.