Bittern Annual Surveys in Britain 1990-2011

Royal Society for the Protection of Birds

Description

This dataset contains results from annual national surveys that are undertaken to monitor the population of Bittern <i>Botaurus stellaris</i> in Britain. The Bittern is a species of conservation concern. Breeding bitterns in Britain are restricted to reedbed <i>Phragmites australis</i> dominated habitat. Suitable habitats within the bittern range (southern Britain and Lancashire) are monitored for booming males annually. Suitable habitats out-with this are surveyed less regularly.

This survey was carried out by the Royal Society for the Protection of Birds (RSPB) and Natural England undertaken within the Statutory Conservation Agencies and RSPB Breeding Birds Scheme (SCARABBS).

Geographic Description

The survey is concentrated in the southern Britain and Lancashire area which holds the core Bittern population.

Data quality

These data have been gathered by trained field-workers and the data are of high quality.

Methods

At the beginning of each breeding season a list of key sites is drawn up based on bittern occupancy of sites in the previous 5 years. Other sites considered to have the potential to hold breeding bitterns are also surveyed. Throughout the season six visits to each site are made. During the site visit, on hearing a boom (display call by a male) the date, time and bearing are recorded. Home ranges are estimated through triangulation of location and bearing of booming (displaying) males heard during each visit. Only those males that are known to have boomed for a week or more are counted in the minimum figures for each year.

In order to verify records and validate the dataset, the data have been mapped and thoroughly checked. RSPB staff and volunteers collected data.

Citation

These data were collected under Statutory Conservation Agencies and RSPB Breeding Birds Scheme (SCARABBS). Please acknowledge RSPB and Natural England in any use of the data.

Rights

CC-BY

Digitised records