Demographic consequences of potential seabird compensatory measures relating to protected breeding populations in the North Sea, UK, from an expert elicitation exercise

The dataset consists of two CSV files containing expert judgements and fitted Beta distribution parameters. Values represent expert estimates of the potential change in breeding success and adult survival resulting from compensatory measures at bird colonies. Expert judgements were collected using the Sheffield Elicitation Framework (SHELF) through a structured online elicitation process. Six experts were selected based on their expertise, career stage, gender and availability. They provided ranges and quantiles for each scenario, which were discussed within the expert group for internal consistency and physical plausibility. Individual judgements were anonymised and combined by the facilitators after each elicitation round. A Beta distribution was fitted to the judgements for each expert, measure and species. Experts reviewed the resulting distributions and probability curves and could refine their judgements following discussion.

The main limitations are that results depend on the selection and judgement of the experts and may be affected by cognitive biases, differences in interpretation or group dynamics. The fitted Beta distributions also impose assumptions about the shape of expert beliefs, particularly in the tails, and the available ranges and quantiles provide limited information about the underlying distributions. Consequently, fitted distributions may be sensitive to small changes in the elicited values and may not fully represent expert beliefs. Experts generally considered the Beta distribution to provide a reasonable representation.

Quality control included checks for internal consistency, ensuring quantiles followed a valid order and fell within the specified ranges, and checks that ranges and quantiles were within physically reasonable limits. Overlap between expert ranges and the spread of quantiles were also assessed. Experts received training and example judgements, with facilitator oversight supporting adherence to the elicitation protocol.