The status of breeding Red-throated Divers Gavia stellata and Black-throated Divers Gavia arctica in Kintyre, Scotland, 2016–2020

Abstract

ABSTRACT Capsule An onshore wind farm monitoring programme carried out across Kintyre, Scotland from 2016 to 2020 provided an insight into the status of the area’s breeding Red-throated Diver Gavia stellata and Black-throated Diver Gavia arctica populations and their current threats. Aims This study provides an example of targeted monitoring undertaken for a renewables development which can inform conservation decision-making at a population and species level. The aims were to: (i) determine the population status of the breeding diver populations; (ii) determine whether the Cour Wind Farm, or other wind farms in Kintyre, have had any effects on the populations; and (iii) identify the most likely conservation threats to breeding divers within Kintyre. Methods Annual breeding diver surveys across Kintyre recorded presence, breeding activity and productivity. Within the Cour Wind Farm site carcass searches were conducted to record any incidences of diver collisions with wind turbines. Results Divers were recorded on approximately one third of waterbodies monitored in each year. The current Kintyre breeding populations are estimated to be 18–23 Red-throated Diver pairs, and between two and six Black-throated Diver pairs. The Kintyre Red-throated Diver population appears to have lower productivity rates than the UK average. Predation and interspecific competition may be limiting breeding success. No Black-throated Divers were observed to have successfully bred in Kintyre from 2016 to 2020, which may be partly due to a shortage of waterbodies with preferred conditions for nesting. No diver collisions were recorded during carcass searches and there is no evidence to suggest that the Cour Wind Farm is influencing the numbers or distribution of divers. Conclusion The Kintyre Red-throated Diver population may be, and the Black-throated Diver population is likely to be, in unfavourable condition. Opportunities for conservation should be considered, particularly to manage waterbodies so that they are optimal for breeding.