Identifying and Diagnosing Population Declines: A Bayesian Assessment of Lapwings in the UK

Ruth King, Stephen P. Brooks, Chiara Mazzetta, Steve N. Freeman and Byron J. T. Morgan

Universities of St. Andrews, Cambridge, Kent and the British Trust for Ornithology

Summary

In this paper we combine data from separate ring-recovery and partial bird census studies to provide indices of estimated abundance for the UK lapwing population (Vanellus, vanellus). Using a descriptive state space model, we demonstrate the decline in population size in relation to directly interpretable parameters describing the demographic characteristics of the population. This allows us to discuss the direct implications for their future management of this important wildlife species. The proposed method extends previous work in this area by removing restrictive Normality assumptions imposed, provides model-averaged inference to help inform management policy and uses information relating to the index variability across time to fully account for this source of uncertainty within the model.

Keywords:

Markov chain Monte Carlo; Model choice; Population Status; State Space Models; Ring Recovery; Census Data; Vanellus vanellus