semiextinction

Semiextinction is a term used in population biology and conservation to describe a situation where a species or population is reduced to a very small number of individuals, but not to complete extinction. This state is precarious, as the remaining individuals may face significant challenges to long-term survival. Factors contributing to semiextinction can include habitat loss, disease, overhunting, or other environmental pressures that cause a dramatic population decline.

Populations in a state of semiextinction often experience a loss of genetic diversity due to the small number of breeding individuals. This reduced genetic variability can make them more susceptible to diseases and less adaptable to environmental changes, further increasing their risk of eventual extinction. Additionally, the Allee effect can become a significant factor. The Allee effect describes a correlation between population density or size and the individual fitness of organisms. At very low population densities, individuals may have difficulty finding mates, cooperating for defense, or effectively exploiting resources, leading to a decline in reproduction and survival rates.

Conservation efforts for species experiencing semiextinction often focus on captive breeding programs, habitat restoration, and the removal of immediate threats. The goal is to increase population numbers and genetic diversity to a level where the species can recover and become self-sustaining in the wild. However, overcoming the challenges associated with semiextinction can be difficult and requires intensive management.