Rare and endemic species: why are they prone to extinction?

Authors: KANİ IŞIK

Abstract: A species is considered to be "rare" if it exhibits any one of the following attributes: (1) naturally occurs in a narrow geographical area, (2) occupies only one or a few specialised habitats, (3) forms only small population(s) in its range. An "endemic" species, however, grows naturally in a single geographical area, the size of which could be either narrow or relatively large. Not all endemic species are rare, just as not all rare species must necessarily be endemic. Many rare and/or endemic species exhibit one or more of the following attributes which make them especially prone to extinction: (1) narrow (and single) geographical range, (2) only one or a few populations, (3) small population size and little genetic variability, (4) over-exploitation by people, (5) declining population sizes, (6) low reproductive potential, (7) the need for specialised ecological niches, (8) growth that requires stable and nearly constant environments. When habitats of a rare and/or endemic species are damaged and/or fragmented by various human activities, the distribution ranges and population sizes of the species will be reduced, leaving them vulnerable to extinction at a much higher rate than other comparable species. Species that experience any of the above attributes must be given priority and monitored and managed carefully in an effort to promote genetic conservation.

Keywords: Rare species, endemism, extinction, population, conservation biology

Full Text: PDF