Any recognized, documented living organism that is at or below a baseline number of existing specimens projected to be the minimal number necessary for normal breeding and continuation of that specie. This condition threatens the organism with extinction. The reason(s) for potential extinction become meaningful only for mitigation. Extinction threatens when a specie’s members cannot locate mating partners or their genetic pool loses the needed variety. Current categories or risk levels of extinction are (1) Endangered: if causal factors continue, survival is unlikely. (2) Vulnerable: soon to be endangered if the causal factors continue. (3) Rare: at risk, yet neither endangered nor vulnerable. Categories are based on standards of the International Union For Conservation Of Nature.