Counting heron nests at Pitsford

Neil Phillips

The heronry at Pitsford Reservoir was surveyed from the air to enable us to accurately count nests.

In early May 2017, the heronry at Pitsford Water Nature Reserve was surveyed using a drone to see if a more accurate count of nests could be established with this method rather than counting from on the ground. The trial proved very successful with 14 nests counted from the drone footage, compared with 10 nests counted from the ground.

Heron nests from above photographed by a drone

The survey was timed so that the eggs had hatched. This meant that adult birds would not be sitting on the nests incubating eggs - and reduced risk of disturbance. 

One flight was sufficient to get the required footage and lasted less than 5 minutes. The drone used was a DJI Phantom Vision 2+. For this survey the height was set at 200ft, so better quality images could be captured in an attempt to see if Egrets were also using the area. It was hoped to get video footage but this was unavailable on the day of the survey.

The drone was piloted by fully qualified, CAA approved and insured pilot, (Josh Hellon). All surveys were carried out under Natural England permission. Please do not fly drones at Wildlife Trust reserves without permission.

Research has shown that drones generally cause minimal disturbance to birds. Observations were made from the ground while the drone was in the air to see how the birds in the area reacted to the presence of the drone. No obvious signs of disturbance were witnessed. As the eggs were hatched, the adult birds are likely to have been away from the nest collecting food.