Diversionary feeding of Kestrels at Gronant, Denbighshire

In 2017, WOS gave a grant to the North Wales Little Tern Group, the community project that supports Denbighshire County Council’s wardening of Wales’ only Little Tern colony. The money was to buy equipment to provide an alternative food source for a local family of Kestrels to reduce the impact of predation on tern chicks. In the event, no diversionary food was taken by any species and it is thought that an abundance of small mammals in 2017 provided the Kestrels with everything they needed, and predation rates on tern chicks was negligible.

In 2018, the equipment bought last year was deployed, and the remaining money used to provide alternate food as Kestrel presence increased and predation attempts became more frequent. Mice were used initially and it took a while before they were taken by Kestrels, which may be a result of their becoming accustomed to taking food items from the station. Small chicken chicks were then provided, which the Kestrels soon started to take. Up to three chicks were placed on the feeding station at a time and stocks were replenished most mornings. A trail camera was used to monitor use of the feeding station and from 2 July, Kestrels began to take chicks fairly consistently. Not all events of Kestrels taking chicks were captured due to camera trap malfunction but a change of camera managed to capture some photos of such instances later on in the season. There was also a surprise visit from a Barn Owl on 8 July that was caught on camera (Barn Owls were rarely seen around the colony during the breeding season).

   

A total of 31 chicks were taken from the feeding station during summer 2018, predominantly by Kestrels, and as supplementary food was taken, less predation of Little Terns was witnessed and there was a reduction in the presence of Kestrels at the colony. Unfortunately the data collected was insufficient to run statistical tests on the relationship between chicks depredated and diversionary food taken.

 

Henry Cook, EU-LIFE Little Tern Project Officer