Dutch Centre For Field Ornithology (SOVON) - Breeding Bird Atlas 1973-1977 - metadata

Study Extent

The Netherlands, 1974-1977. Fieldwork was carried in squares based on a 5 km grid. All 1971 squares except one very small one were surveyed.

Sampling

The following general information was gathered for each square. The year from which the data originate, the survey completeness and some other relevant factors such as soils, lack of standing fresh water, heath, coniferous woods, broad-leaved woods and moorland. For all observed species the breeding evidence was note using one of 16 codes subdivided into three categories: Confirmed breeding, probable breeding, possible breeding or present. For the first two categories an estimate of the number of breeding pairs was made.

Quality Control

The data was validated by district coordinates

Method steps

1. 1. Gathering general information about the square 2. observation of the breeding birds and noting the breeding evidence using the 16 codes provided 3. making an estimate of the number of breeding pairs 4. validation by district coordinates

All Dutch breeding birds.

1. Avis
   common name: Vogels rank: class

The Netherlands