In addition to the 10-12 million of migratory birds, the Wadden Sea also supports large numbers of breeding birds. For several breeding bird species like eurasian spoonbill, oystercatcher, avocet, kentish plover, common redshank, lesser black-backed gull, gull-billed tern and sandwich tern, the Wadden Sea is among the most important breeding sites in Northwest-Europe. Several species are included in Annex I of the EU-Bird Directive or listed as Species of European Concern (SPEC). At national level, many Wadden Sea breeding birds represent an important share of national breeding bird populations and are listed as Red List species.

Monitoring of breeding birds in the Wadden Sea has been carried out by the Joint Monitoring Group for Breeding Birds (JMBB) in the framework of the Trilateral Monitoring and Assessment Program (TMAP) since 1991 (Fleet et al., 1994; Melter et al., 1997; Rasmussen et al., 2000; Koffijberg et al., 2006). The monitoring scheme currently focuses on 35 bird species that are considered characteristic for the Wadden Sea ecosystem. Common breeding birds (8 species) are counted annually in 103 representative census areas evenly distributed over all regions and habitats of the Wadden Sea Cooperation Area. Colonial and rare breeding birds (27 species) are difficult to survey with census areas and are counted by annual complete counts in the entire Wadden Sea. Once every 5 years, a total count of all species, including common species, is carried out (1991, 1996, 2001, 2006, interval now changed to once every 6 years). The monitoring scheme aims to assess and detect population size, distribution and population trends in Wadden Sea breeding birds. Fieldwork is standardised and carried out according to trilaterally harmonised methods (Hälterlein et al., 1995) by nearly 500 ornithologists, mainly consisting of staff of NGOs, governmental bodies, site managers and volunteers. A so-called Quality Assurance Meeting (QAM) is organised regularly to provide a platform for exchange of field experience among counters and discussion of specific counting pitfalls (e.g. Blew, 2003).

This website aims to present a regular update of trends in breeding bird numbers, for those species were trend calculations are possible (at the moment 26 species) and that have been monitored from 1991 onwards.  Trends, methods, an overview map of census sites and important references about monitoring of breeding birds you can find here as latest version June 2011.