This report reviews the suitability of methods used to calculate the scale of Artificial Nest Structures (ANS) provided as compensation measures for Kittiwake mortality at offshore wind farms in English waters, due to turbine collision only. This report was revised in October 2025 and republished on 30-10-2025, correcting an error in Table 5. The recalculated compensation populations in the original report did not match the underlying fecundity values in the column headers. In addition, a link to helpful computer code was added to Appendix 3 (see below).

As part of the suite of work for the BTO Northern Ireland Science Plan 2023–2028 for DAERA/NIEA, BTO was asked to provide an analysis and associated report to investigate climate change related change in seabird populations in and around Northern Ireland. In this report, we update previously estimated projections of change in seabird populations (Davies et al. 2023) based on newly available datasets, including data from Seabirds Count and updated NEMO and C3S oceanographic data. We also discuss the reliability of existing Interreg VA/MarPAMM projected changes, and the likely extent to which climate change is already driving alterations to seabird abundance. Overall, the population of seabirds in the Interreg VA/MarPAMM region is predicted to decline in presence and abundance by 2050 under climate change.

This report assesses the capability of a Spoor AI camera system with both mono-vision (single-camera) and stereo-vision capabilities for bird monitoring deployed at the European Offshore Wind Deployment Centre in Aberdeen Bay using both theoretical considerations and onshore and offshore field trials.

This document presents a review of existing methods for collecting seabird flight height data and their potential to produce flight height distributions that might be used in CRMs. The strengths, weaknesses, and limitations of different methods are identified and sources of measurement and sampling error, uncertainty and bias assessed. Best practice recommendations are provided for prominent methods and how data might be best utilised to inform stakeholders is considered.

This study uses a population modelling approach to explore the effects of changes in rates of productivity, survival, and settlement on population growth in the English population of Hen Harriers.