Monitoring breeding birds, the JMBB program
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,
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.
2011. Trends in breeding birds in the Wadden Sea 1991-2006.
www.waddensea-secretariat.org, Wilhelmshaven, Germany.