Population viability analysis for bird conservation: Prediction, heuristics, monitoring and psychology

The primary roles for population viability analysis (PVA) in bird conservat ion are to predict the consequences of human actions for populations, and t o assist in the design of research and monitoring programs. PVAs have limit ations that compromise their ability to predict the future accurately. But all predictions are error prone. The lack of completely reliable and verifi able predictions does not detract from the utility of PVAs because their pr imary output is to reinforce the rigour and transparency of environmental d ecision making. The imperative for PVAs is driven by the weaknesses of alte rnative approaches that rest on undefined and unrepeatable subjective proce sses. Subjective estimation is known to be biased and inaccurate and this r eview contends that many alternatives to PVA will produce worse results.