How attractive is a particular grassland for meadow birds? And is biodiversity improving or declining? Researchers at Wageningen University & Research's Agro Food Robotics know everything there is to know about this. Together with 4D Precision Natuurbeheer (4D Precision Nature-management), an initiative of Orphiction B.V., they are developing a method to monitor grasslands from the air. This creates new opportunities for agricultural nature-management.
More and more farmers in the Netherlands want to do their bit for biodiversity. For example, they choose to mow grassland less often, so that meadow birds and other animal species can find refuge there. Making a meadow suitable for meadow birds does not happen by itself, emphasizes Janne Kool, researcher in Agro Food Robotics at Wageningen University & Research. "Fields in the Netherlands often have very dense vegetation, which reduces the insect population significantly while making it difficult for young chicks who need to walk through the vegetation," she explains. "It often takes several years of extensification before such an area becomes attractive for meadow birds."
If farmers and other agricultural land managers know a grassland’s condition, they can adjust their policy accordingly. Mowing at a later time and removing the grass, for example, or using less fertiliser. However, many grasslands are difficult to access, often because they are protected, or simply because one chooses not to disturb the environment by walking in it.
What cannot be done via the land, might be possible from the air. It was this idea that prompted the research Kool is doing as part of the project AGROS (2020-2023). In this research, biologists with knowledge about birds work closely with plant scientists, and experts in the field of artificial intelligence, camera and vision techniques.
"We equipped a drone with a multispectral camera and flew it over peat grasslands. As a control, ecologists, on the ground, also determined the state of the grassland," says Kool. "We are now investigating how we can use aerial images to determine how suitable the grassland is for meadow birds."
Searching for birds' nests
Kool and her colleagues are now looking for the best time to fly the drone: April, or May - when everything is in bloom. The next step will be to find and identify which species of birds built the nests. "In 2022 we will investigate whether this method is also suitable for monitoring grasslands on clay and sandy soils."