In Order to Be Considered Extinct, a Species Can't Be

Question

In order to be considered extinct, a species can't be found
A) at all, in the wild or in captivity at the present time.
B) at all, presently or during the past 10 years.
C) at all, presently or during the past 50 years.
D) in the wild presently but may exist in captivity.

Accepted Answer

A species is considered extinct when there is no reasonable doubt that the last individual has died, typically after exhaustive surveys in known or expected habitats have failed to record an individual over a time frame appropriate to the species' life cycle, often considered to be 50 years.