Breeding bird protection with drones: find, measure and monitor nests

Lapwing, black-tailed godwit and Montagu's harrier nest on the ground, well camouflaged in meadow and field. There, mowing and harvesting, predators and disturbance threaten them. Anyone who wants to protect them must find the clutches first: over a large area, in a short time and without disturbing the brood.

On foot or with binoculars, this takes a lot of time. For the Montagu's harrier, following the female's flight from several vantage points takes several hours to days per nest. White-tailed eagle eyries are usually checked from the ground twice a year, in March and June. The result is often a high number of undiscovered and therefore unprotected nests.

Black-tailed godwit, lapwing, redshank, curlew, common snipe, dunlin and ruff are the target species in meadow bird protection. Finding the nests of these species has become much easier with a thermal drone combined with POICloud and POIApp. On the ground, the POIApp guides helpers to the nest, and with the POIApp RTK receiver even to the centimeter.

On managed land, what matters is to find clutches and chicks before mowing, mark them and fence them off if necessary. The position can also be passed on to the farm machine as ISOXML.

With the DJI Matrice 4TD, a button press on the remote control is enough: the laser rangefinder and RTK GPS together measure the nest from over 100 m away, so you stay at a distance. POIConnect transmits the marker in real time to POICloud and to the POIApp on the team's smartphones. With the DJI Mavic 3T, too, you locate the find from the air and send it straight to the helpers.

Whether a nest stands out in a thermal image depends on ground resolution and signal quality. The guideline values come from our practical experience and from the research of Israel & Reinhard (2017).

The Montagu's harrier breeds mainly in grain fields, where its clutch is threatened by early harvest and predation. It is on the Red List in category 2 (endangered); in Brandenburg there were still 23 confirmed breeding pairs in 2024. The few pairs are spread over several hundred km², so finding nests is the bottleneck.

This is how the association Wiesenweihen- und Naturschutz Nordostdeutschland works: gather observations from various sources, search with the drone in a targeted way at the sites of food passes, measure and fence the nests, and check them later with the drone.

The white-tailed eagle is Germany's largest bird of prey and, with around 1,000 breeding pairs (as of 2024), is considered not threatened. Its eyries can grow up to 4 m high and weigh 1 t. Traditionally, rangers and volunteers check known eyries twice a year, in March and June, from the ground with binoculars and spotting scopes. The difficulty lies above all in finding new eyries. On top of that come a lack of trained staff and tight budgets.

POICloud connects drone, team and everyone involved: fields, missions and finds are in one place. It grew out of fawn rescue, was developed together with hundreds of fawn rescuers and trained with thousands of thermal images. We transferred every development one to one to breeding bird protection and adapted it for clutches, chicks and breeding birds. In wildlife rescue, over 200,000 hectares have already been searched with the platform, and in breeding bird protection projects from Schleswig-Holstein to Bavaria work with it.