This model shows the events that ultimately lead small populations to become increasingly vulnerable as they spiral toward extinction.
[1] The first two (R and D) deal with environmental factors that have an effect on the ecosystem or community level, such as disturbance, pollution, habitat loss etc.
These events can include rapid loss of population size due to disease, natural disasters, and climate change.
[2] One example of the role of genetics in extinction occurs in the case of fragmented metapopulations of southern dunlins (Calidris alpine schinzii) in SW Sweden.
[3] Demographic factors that are involved in extinction vortices include reduced fecundity, changes in dispersal patterns, and decreased population density.