An Integrated Population Model from Constant Effort Bird-Ringing Data

Cave, V. M., King, R. and Freeman, S. N.

University of St. Andrews and British Trust for Ornithology


Data from the British Trust for Ornithology's Constant Effort Scheme, an annual bird-ringing programme in which catch effort is standardised, are routinely used to index abundance, productivity and adult survival. Efficient models have been developed for each. Such a monitoring scheme, based on ringing across a number of sites, is perhaps unique in providing this combination of demographic information and makes the data particularly amenable to an integrated approach to population modelling. We develop a Bayesian approach and a deterministic population model uniting abundance, productivity and survival. The method is applied to Constant Effort Site data for Sedge Warblers Acrocephalus schoenobaenus. The possibility of ``transient'' birds needs to be incorporated within the model and we demonstrate how the current methodology can be efficiently extended to use data from multiple recaptures within individual years.


Bayesian approach; Capture-recapture; Constant Effort Site scheme; Sedge Warbler Acrocephalus schoenobaenus; Transients.