APEM has contributed to new research that confirms the value of ultra-high resolution aerial surveys for counting seabirds and mapping their distribution, pointing the way to improved techniques for environmental impact assessments.

The research, published in the respected journal British Birds, looked at red-throated divers, a protected species found in large numbers at UK sites from Shetland to the east coast of England.

APEM aircraft surveying an offshore wind farm

New bird counting techniques

Although the birds have been recorded in numbers large enough to warrant international protection at some sites, researchers suspected that previous estimates had been too low. Traditionally these estimates have been gathered by observers with binoculars who manually count birds from the shore, in boats or from aircraft.

Newer techniques pioneered by APEM instead use ultra-high resolution digital cameras fitted to survey aircraft to capture thousands of images over an area, with the aircraft flying in a carefully configured grid-based flight plan to ensure high quality data.

The images are then analysed on the ground by ornithologists to determine the species, numbers and flight heights of the birds. Well over 90 per cent of the birds captured in the images can be identified for their species.

Improved estimates

A series of extensive aerial surveys carried out by APEM on behalf of Natural England, provided the opportunity for ornithologists from the company to lead on and contribute to the new research.

APEM’s head of ornithology, Dr Mark Rehfisch, said: “Data on the numbers and distribution of seabirds is not just of academic interest. It’s used to help determine important decisions in the real world, such as which areas should be protected and whether offshore windfarms can be built.

Our innovation of using digital aerial surveys to capture images of the birds has given us much more accurate data, confirming that previous estimates of the numbers of red-throated divers in the area were too low.

The peak estimate of 14,161 red-throated divers recorded using high resolution aerial surveys in February 2013 was more than twice the estimate of 6,466 that had been recorded for the same area using visual surveys in 2008.