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Guillemots of Sark - 2024 Survey

Lynda Higgins talks about the Guillemots of Sark and the importance of the survey.

We were delighted to be asked to help carry out a survey of the Guillemot colonies in Sark.

Traditional methods of counting these seabirds, which form large, dense colonies on cliffs and rocky islands, can be disruptive and inefficient. By using a Drone (UAS) we aimed to achieve accurate counts with minimal disturbance. This project was conducted for Lynda Higgins of La Société Sercquaise, who highlighted the limitations of traditional surveys, such as potential disruption to the birds' feeding patterns and difficulty in obtaining clear images from a moving boat.

Using Yolvo8 we were able to put footage and images into the software and get an accurate count of Guillemots on these isles.

Our primary objectives for this survey were to determine the total number of guillemots in each colony, potentially identify and count the number of chicks, if carried out later, minimise disturbance to the birds and their habitat, and collect data to inform conservation efforts. We used the DJI Mavic 3 Pro, chosen for their high-resolution imaging capabilities and ability to capture detailed footage from a safe distance.

The methodology involved several steps to ensure the success and ethical integrity of the survey. Prior to the flights, we obtained necessary permits, conducted a risk assessment, and established flight paths using mapping software. During the flights, the drone was operated at a 100ft distance from the seabirds at all times to avoid disturbing the birds. High-resolution images and videos were captured along these pre-programmed paths, providing a comprehensive view of the colonies.

On May 21st, we conducted a successful test flight over the Burons to establish a safe route and ensure no disruption to other nesting birds. This test flight, monitored by spotters Matthew Stockreiter and Liz Sweet, allowed us to refine our approach. The full survey on May 22nd involved flying the drone from the harbour, with Lynda Higgins and Liz Sweet monitoring from the cliff. The drone captured detailed images and videos of the colony, enabling an accurate count of 373 individuals, which increased to 508 when incorporating birds-eye images that revealed hidden birds.

Our attempt to survey Les Autelets on May 23rd, however, it was hindered by high winds and herring and lesser black-backed gulls. Despite efforts to mitigate disturbance by moving the drone offshore, the presence of these seabirds forced us to abort the mission. This experience highlighted the challenges of conducting surveys in certain areas and underscored the need for alternative approaches or timing to avoid disruption.

Overall, the use of drone technology in this survey demonstrated its effectiveness in providing accurate, high-quality data with minimal disturbance to wildlife. The findings from the Burons colony survey highlighted the advantages of bird's eye views for more accurate counts and the importance of using high-resolution sensors for detailed imaging. Despite the challenges faced at Les Autelets, the survey underscored the potential of drones in wildlife conservation and provided valuable insights for refining future methodologies. This approach not only enhances our ability to monitor seabird populations but also supports ongoing conservation efforts by providing precise and reliable data.

This is a fantastic clip from Sue Daly’s original Wild Islands series. This clip from ‘Wild Sark’ shows you a little more about the Guillemots around Sark.

The survey was repeated on the 23rd and 30th June. The Burons and Les Autelets were both successfully surveyed. Three counts provides a good average over the course of the season to establish an accurate count of the birds in Sark.


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