Quantifying Conservation Concern - Bayesian Statistics and the Red Data Lists
Steve Brooks, Steve Freeman, Jeremy Greenwood, Ruth King and Chiara Mazzetta
Universities of Cambridge, St. Andrews and Kent and the British Trust
for Ornithology
Summary
It is important to have accurate and precise
measures of rates of population decline when prioritizing species for
conservation action. For species that are still widespread, this
inevitably means gathering representative sample data rather than
undertaking a comprehensive census. We have found that considerable
improvements can be made in interpreting declines by explaining annual
fluctuations in terms of explicit and realistic population models
(rather than merely fitting trends of an arbitrary mathematical form to
the census data), through the simultaneous modelling of data from the
census with those providing information on the demographic rates
employed in the population models, and through adopting a Bayesian
rather than a frequentist statistical approach. In this paper we
provide details of the Bayesian approach and discuss the results and
their implications for wildlife population monitoring.