Journal Article

Significance of Sighting Rate in Inferring Extinction and Threat

McINERNY, GREG J., CRIBB, PHILLIP J., ROBERTS, DAVID L., DAVY, ANTHONY J.

2006

Overview

We are now entering a time of immense environmental upheaval in which, increasingly, experts are required to provide conservation assessments. Quantitative assessment of trends in species' range and abundance is costly, requiring extensive field studies over a long period of time. Unfortunately, many species are only known through a few \"chance\" sightings or a handful of specimens, and therefore extinction may be even harder to ascertain. Several methods have been proposed for estimating the probability of extinction. However, comparison within and between species is difficult because of variations in sighting rates. We applied a probabilistic method that incorporates sighting rate to the sighting record of Vietnamese slipper orchids (Paphiopedilum). The method generates a probability that another sighting will occur given the previous sighting rate and the time since last observation. This allows greater comparability between species discovered at different times. Its predictions were more highly correlated with the World Conservation Union criteria than previous methods. Trends in data collection and the political climate of a country, which affects access to material, are important potential sources of variation that affect sighting rates. A lack of understanding of the process by which data are generated makes inferring extinction from sighting records difficult because extinction status depends on how the sighting rate varies. However, such methods allow rapid conservation prioritization of taxa that are poorly known and would otherwise go unassessed.

• Publisher: Blackwell Publishing Inc,Blackwell Science,Blackwell
• Subject: Animal, plant and microbial ecology / Applied ecology / Biological and medical sciences / collection data / Conservation of Natural Resources - methods / Conservation of Natural Resources - statistics & numerical data / Conservation, protection and management of environment and wildlife / criterios de lista roja / datos de colección / declinación de especies / especimenes de herbario / Fundamental and applied biological sciences. Psychology / General aspects / herbarium specimens / Models, Biological / Models, Statistical / Orchidaceae - physiology / Paphiopedilum / Parks, reserves, wildlife conservation. Endangered species: population survey and restocking / Population Density / red-list criteria / Research Notes / species decline / Species Specificity