A Nonparametric Test for Extinction Based on a Sighting Record

Extinctions of plant and animal species are rarely observed directly and must be inferred from sighting or collection records. The inference about extinction that can be drawn from a sighting record depends on the sighting rate. Existing methods assume that the form of the sighting rate is known and may be sensitive to deviations from the assumed form. A simple nonparametric test is proposed that makes minimal assumptions about the sighting rate. The test is illustrated by application to collection records of nine Mauritian orchid species. Corresponding Editor: B. Shipley