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

The primary roles for population viability analysis (PVA) in bird conservation are to predict the consequences of human actions for populations, and to assist in the design of research and monitoring programs. PVAs have limitations that compromise their ability to predict the future accurately. But all predictions are error prone. The lack of completely reliable and verifiable predictions does not detract from the utility of PVAs because their primary output is to reinforce the rigour and transparency of environmental decision making. The imperative for PVAs is driven by the weaknesses of alternative approaches that rest on undefined and unrepeatable subjective processes. Subjective estimation is known to be biased and inaccurate and this review contends that many alternatives to PVA will produce worse results.