Population Monitoring

Censusing of Brent has been carried out periodically since the 1960s.
All-Ireland censuses were initiated by Major Robin Ruttledge in 1960/61, continued by the Irish Wildfowl Committee (latterly the Irish Wildbird Conservancy) and then the Forest and Wildlife Service (predecessor of National Parks & Wildlife Service) up to the 1970s. Michael O'Briain establishment of the Irish Brent Goose Study in 1983 and organised censuses up to the early 1990s.

The recent phase of monitoring began in 1996 organised by the IBGRG through WWT and in conjunction with the Wetland Bird Survey (UK-WeBS) and Irish Wetland Bird Surveys (I-WeBS). For the last decade or so, bi-annual censuses have been carried out in October and January at all major sites holding Brent. The principal objective of the autumn census is to get an accurate assessment of the size of the population and an estimate of productivity in the previous breeding season. These basic parameters - the number of individuals in the population and the proportion added in any one year - are fundamental to understanding the trajectory of the population and the role of factors contributing to increases, decreases or stability. During autumn the population tends to be concentrated at just a few sites and the centre of gravity moves from western Icelandic sites in early and mid-September to Irish sites in late September through to the end of October.







The survey has gradually become more international and since 19xx, synchronous censusing has been occurring in Iceland, Ireland, W Scotland and France. The objectives of the January survey are quite different. At this time the population is much more widely dispersed, the major staging concentrations at Strangford Lough (Down) and Lough Foyle (L'Derry) having dispersed from November. The primary aim is thus to monitor the importance of sites for the species during the mid-winter period.