Any of the species vulnerable to becoming endangered within all or much of its range in the near future
A threatened species is one that is likely to become an endangered species in the near future throughout all or a significant portion of its range. It may be a species of animal, plant, etc. that is susceptible to endangerment in the foreseeable future. One way to identify a threatened species is through population dynamics measure of critical depensation. Criical depensation pertains to the level of depensation that is high enough that the population becomes incapable of sustaining itself. This coincides with the decline of population such that it drops below a critical level. If the population continues to decline it may possibly lead to the species' local extinction. Thus, critical depensation is measured to evaluate the degree of endangerment of a particular species.
The International Union for Conservation of Nature considers threatened species as a group that can be further categorized into: vulnerable species, endangered species, and critically endangered species. Vulnerable species, compared to other categories, are the least at risk of extinction. The endangered and the critically endangered species are more at risk of being wiped out altogether.