Drones are a practical alternative to more traditional methods of counting seabirds for environmental assessments of offshore wind farms, a trial in the UK has proved
NIRAS has completed a successful trial using drones for a bird study on the east coast of England. The innovative study was funded by DONG Energy in order to support the ornithology assessment for the Hornsea Project Three Offshore Wind Farm.
“The breeding grounds and migration routes of birds play a significant role in the planning of offshore wind farms, as large wind farms can pose risks such as collision, displacement and disturbance to birds,” says Tim Norman, Managing Director NIRAS Consulting UK.
In the trial, which was concluded in partnership with the Royal Society for the Protection of Birds, NIRAS used drone captured imagery to survey cliff-nesting seabirds at Bempton Cliffs on the east coast of England.
Drones an alternative to boats
“Previously, cliff-nesting seabirds at this colony have been counted visually from a boat with such surveys reliant on favourable weather conditions, a factor that has significantly limited the number of years in which complete colony counts have been possible,” says Tim Norman.
Using a NIRAS MikroKopter piloted by Dragons Eye, this trial conducted a number of drone flights to determine if counts of cliff-nesting seabirds were feasible from drone-captured imagery. If successful this method would provide contemporaneous and more accurate counts of cliff-nesting seabirds.
No disturbance to nesting birds
The success of the trial was dependent on the drone being able to get close enough to the colony to provide imagery of a resolution sufficient to distinguish between the different bird species, whilst ensuring that disturbance to breeding seabirds was avoided.
It was paramount that disturbance to breeding seabirds was minimised as any disturbance could have been disastrous for the breeding success of birds in terms of disturbance and potentially desertion of nests. In order to monitor disturbance, a NIRAS ornithologist was present at all times observing the reactions of birds to the drone. Any disturbance would have resulted in the abandonment of survey work.
However, concerns in relation to disturbance proved to be unfounded with the birds showing minimal interest in the drone. The photos taken by the drone also proved to be detailed enough to enable the separation of guillemots and razorbills, two species of auk that look very similar when observed from a distance.
The lack of bird disturbance and high resolution photos captured by the drone led the trial to be declared a success. All parties were confident that drone surveys offered a practical alternative to more traditional methods of counting cliff-nesting seabirds and it is hoped that this approach will be implemented in future whole colony counts.
Reduced uncertainty in assessments
The use of drone technology for survey work builds on NIRAS’s growing reputation for problem-solving using innovative technological techniques to reduce uncertainty associated with areas of assessment. NIRAS has also collaborated on the use of radar systems in the offshore environment combined with laser rangefinders and have been involved in the development of a new survey concept that will utilise LiDAR technology as part of aerial bird surveys.