The role of ringing in integrated population monitoring of Anatidae in the United Kingdom

An Integrated Population Monitoring (IPM) programme is being developed for wildfowl (Anatidae) in the United Kingdom. This aims to monitor the demographic processes that regulate population size and distribution, to identify requirements for the maintenance of populations and to provide data to predict the effects of demographic or environmental changes on populations. Ringing plays a central role in this programme, in particular for monitoring survival rates and movements. Data from marked individuals are also important for determining the effects of hunting on wildfowl populations. Despite the long history of wildfowl ringing in the United Kingdom, current ringing activity does not fulfil the objectives of IPM. In particular, the lack of computerisation of data, outdated survival estimates and analysis methods (especially for ducks), geographical bias in ringing activity, declining sample sizes and lack of comprehensive harvest data for quarry populations all place a serious constraint on the application of IPM to wildfowl in the United Kingdom. These problems have been addressed in the development of a ringing strategy for wildfowl in the United Kingdom, which will be implemented by The Wildfowl & Wetlands Trust as part of an Integrated Population Monitoring programme for wildfowl.