Species protection plan for birds of marshes, bogs and swamps: trends in numbers
The species protection plan for birds of marshes, bogs and swamps covers 13 species. Most species in this group have been increasing in numbers since 1990 or have remained stable; the hen harrier and great reed warbler are declining.
| Trends in marshland birds in the species protection plan | ||
| Species | Short-term target | National trend since 1990 (annual percentage increase or decrease) |
| Bearded tit | decline halted | stable |
| Hen harrier | decline halted | decline (- 4%) |
| Great reed warbler | decline halted | decline (- 5%) |
| Night heron | decline halted | unclear |
| Spotted crake | decline halted | increase (+ 4%) |
| Purple heron | decline halted | increase (+ 4%) |
| Bittern | decline halted | increase (+ 3%) |
| Savi's warbler | decline halted | unclear |
| Little bittern | decline halted | more or less stable |
| Black tern | decline halted | more or less stable |
| Bluethroat | at least stable | increase (+ 5%) |
| Red-crested pochard | at least stable | increase (+ 29%) |
| Spoonbill | at least stable | increase (+ 7%) |
| Source: NEM (SOVON, CBS) | CBS/NC/Oct02 | |
Trends
The species protection plan has several short-term (2000-2004) targets. The first is to halt the decline (ongoing for several decades) in national numbers and/or distribution of the bearded tit, hen harrier, great reed warbler, night heron, spotted crake, purple heron, bittern, Savi's warbler, little bittern and black tern. This will probably be achieved for the seven species that increased or were stable between 1990-2000. The hen harrier and great reed warbler are currently declining, and the night heron shows no clear trend as yet.
The second short-term target is to maintain the numbers and distribution of the bluethroat, red-crested pochard and spoonbill. This target has been achieved, as numbers of all three species are currently increasing.
There is also a long-term target: by 2018 (if the national ecological network is in place), all 13 species must have sustainable populations. This means there must be sufficient numbers, spread sufficiently over the country. For many species this target has not yet been achieved.
Technical note
The information is based on the Ecological Monitoring Network's national network for monitoring breeding birds. The trends have been statistically tested. The national trend for the black tern has been calculated for 1993-2001; the trends for all other species have been calculated for 1990-2001.
References
- Dijk, A.J. van, M.J.T. van der Weide, R. Kleefstra, D. Zoetebier en C. Plate (2001). Kolonievogels en zeldzame broedvogels in Nederland in 1999. SOVON-monitoringrapport 2001/08. SOVON Vogelonderzoek Nederland. Beek-Ubbergen.
- LNV (2000). Beschermingsplan moerasvogels 2000-2004. Directie Natuurbeheer. Ministerie van Landbouw, Natuurbeheer en Visserij. Wageningen.
