Recording Methods

In November 2007 the British Trust for Ornithology, in partnership with the Scottish Ornithologists' Club and Birdwatch Ireland, started a four-year winter and breeding season atlas project aimed at revising the distribution maps and population estimates from the 1981-84 Winter Atlas and the 1988-92 Breeding Atlas. The winter season spans the months of November to February inclusive and for most species the breeding season will be considered to extend from the start of April to the end of July.

The Beds Bird Club project for the county atlas will operate under the same methodology as in the previous two county projects, and will capture information at the scale of a tetrad (2-km x 2-km square). This means that there will be some small differences in the data collection between the local and national atlas information, but this will allow us to compare the county results directly with the two previous sets of results.

The methodology for the national atlas project will comprise two components: Roving Records and Timed Tetrad Visits.

The Roving Records method will aim to build complete species lists for each 10-km square. During the breeding season additional behavioural data will be collected to assign possible, probable or confirmed breeding status on the basis of standard criteria.

For Timed Tetrad Visits, the requirement is that visits will be made to a minimum of eight tetrads in each 10-km square. Two visits to a tetrad should be made in one of the summers and two visits to a tetrad in one of the winter seasons. That is a total of 32 field visits, spread across the four years. This should be easily attainable in a densely populated county like Bedfordshire, but we still need volunteers to sign up for tetrads. Each visit will need to last at least one hour, and preferably two hours. It is expected that during that time a representative sample of the available habitat will be covered. During these visits the emphasis will be on counting all birds encountered, as this data will primarily be used to determine abundance.