Every year, volunteers across the UK take part in the BTO/RSPB/JNCC Breeding Bird Survey (BBS), recording breeding birds in randomly selected 1-km squares (stratified regionally by observer availability) to robustly monitor population trends of some UK bird species. However, the chances of randomly selected squares containing rarer bird species and the habitats of interest that only cover a small proportion of the landscape are low, limiting our ability to monitor population changes. The work reported here examines options for increasing coverage of rare species and of assemblages occupying certain habitats of interest within the BBS framework, by including additional strata based on habitat type. It also assesses the benefits and risks of including an additional stratum based on accessibility to increase volunteer uptake in large regions with low observer density and many inaccessible areas. Volunteer recruitment is often difficult in these regions because randomly selected unmonitored BBS squares may require long drives, difficult walks and over-night camping.

The purpose of this work was to develop a method for analysing digital aerial ornithology survey data, to derive species-specific flight heights. The focus of this work has been to develop an approach to analysis, rather than analysing a comprehensive dataset to derive generic flight height values. Although the project has been successful in developing such an approach to analysis, the BTO and Steering Group for the work emphasises that the values presented in this report are not intended to be used to inform assessments. Any party undertaking an ornithological collision risk assessment should seek advice from the relevant regulators and statutory nature conservation bodies on appropriate flight height values and avoidance rates to use. This report does not constitute such statutory advice.

Earth Observation data offer great potential for a range of terrestrial surveillance and management issues. Living Maps – land cover maps with a focus on priority semi-natural habitats – are being developed using state of the art data and remote sensing analyses. This report scopes out how volunteers could be engaged in the validation of the Norfolk Living Map, and how transferable proposed the techniques are to other regions of the UK.

Trends in numbers, breeding success and survival for UK breeding birds.

The BirdTrends 2020 report is a one-stop shop for authoritative information about the population status of the common breeding birds of the wider UK countryside. The report is based on data gathered by the many thousands of volunteers who contribute to BTO-led surveys.