A large population of the rare wall brown butterfly has appeared in the Bovenkerkerpolder in Amstelveen.
Biologist Aad van Paassen, who also volunteers with nature education organisation IVN in Amstelveen, spotted the insects during a 1.5-kilometre walk across the farmland.
He counted 141 wall brown butterflies along the route.
Changes in farmland habitats
The high count is notable because the farmland butterfly population has declined steeply across the Netherlands since 1990.
Van Paassen noted that rural areas have changed significantly as farmers focus on keeping their businesses running.
In this polder, farmer Remco planted strips of flowers alongside the ditches on his land to support the butterfly.
Pointing to one of the flower strips, Van Paassen called the dense mix of plant species ideal ground for the species.
Want to explore more local wildlife? Read our guide to nature in and around Amsterdam.