ABV - Common breeding birds in Flanders, Belgium

Study Extent

-Describe the long-term abundance from a set of 101 general breeding birds in Flanders. -Describe the distribution of the selected species and the changes over time. -Describe (relative) densities of a number of species

Sampling

The atlas of breeding birds in Flanders (https://www.gbif.org/dataset/81c5a091-6e94-40db-a2a4-48f4de42d410) was based on territory mapping in 5×5 km UTM-squares with additional information collected in a subset of 8 1×1 km squares (Vermeersch et al., 2004). So, since we already had information in over 5,000 1×1 UTM-squares, we chose that grid as a basis for the new census. The grid was then randomly stratified over 6 habitat types (farmland, woodland, urban, suburban, heathland and marshland) and finally,6 points were randomly assigned to each grid cell (Fig. 1). Each point has to be counted three times in a year in predefined periods (DD/MM): 01/03-15/04, 16/04-31/05 and 01/06-15/07. All six points in a square have to be counted on the same day and subsequent counts of the same points in different periods should lie apart for at least two weeks. A separate study (Onkelinx et al., 2006) was carried out to estimate the sample size needed to calculate good indices for the majority of common species. The study was based on density-figures in 1×1 km squares from the previous atlas. Finally, 1200 squares were randomly chosen from the above mentioned grid. Considering the number of volunteers and to increase geographical coverage and sample size, we chose for a three-year cycle. Initially, every point had two observation circles around it (50 and 150 meters), but after consulting our Dutch colleagues from SOVON, we chose not to use these circles. Instead, this system is preserved for a calibration study in 10 % of all squares that should allow us to calculate density functions for some of the commoner species (see also Van Turnhout, 2006). In this study, all observations will be drawn on a map, while in the ‘normal’ scheme this is not requested. This fieldwork is carried out by INBO staff. The voluntary network Starting from the existing network in the BBV-project, approximately 40 regional coordinators were found throughout Flanders. Natuurpunt and INBO started giving lectures about the project and its methodology in March. Although this was a rather late start, volunteers were very eager to join in and after a few weeks, over 300 squares (for 2007) were already assigned to approximately 150 different people. For the following years, success will be even higher since some regional groups chose to start only next year. All volunteers received maps, field forms and a methodology folder (Bird Census News 2007: 20/1)

Quality Control

All records are validated. All data obtained from atlas fieldwork were collected on standard recording forms. These were sent to the regional coordinator who checked them thoroughly and contacted volunteers in case of any obvious anomalies.

Method steps

1. Bird Census News 2007: 20/1

Aves

1. Aves
   rank: class
2. Suliformes
   rank: order
3. Strigiformes
   rank: order
4. Psittaciformes
   rank: order
5. Accipitriformes
   rank: order
6. Anseriformes
   rank: order
7. Apodiformes
   rank: order
8. Caprimulgiformes
   rank: order
9. Charadriiformes
   rank: order
10. Ciconiiformes
    rank: order
11. Columbiformes
    rank: order
12. Coraciiformes
    rank: order
13. Cuculiformes
    rank: order
14. Falconiformes
    rank: order
15. Galliformes
    rank: order
16. Gruiformes
    rank: order
17. Passeriformes
    rank: order
18. Pelecaniformes
    rank: order
19. Piciformes
    rank: order
20. Podicipediformes
    rank: order

Geographically, Flanders is generally flat, and has a small section of coast on the North Sea. Much of Flanders is agriculturally fertile and densely populated, with a population density of almost 500 people per square kilometer (1,200 per square mile). It touches France to the west near the coast, and borders the Netherlands to the north and east, and Wallonia to the south. The Brussels Capital Region is an enclave within the Flemish Region. (Wikipedia)