The Gilberginsel - also known colloquially as Vogelinsel - is located in the Biggesee about 3.5 km from Attendorn. Only a narrow stretch of water separates the island from the shore. The island itself is the only island in the Biggesee and is uninhabited. Together with the adjacent water area, the entire island has been a nature reserve since 1985. The size of the nature reserve is 96 hectares. The main reason for its protected status was the settlement of a gray heron colony.
Until 2007, the island was mainly planted with spruce trees, but most of these fell victim to storm Kyrill. Although many nest trees were destroyed by the storm, cormorants began to breed on the island just one year later. Today, gray herons and cormorants share the few nesting trees near the shore. The largest grey heron colony in the Olpe district breeds here. After their dives, the cormorants sit on branches or stones with their wings outstretched and allow their wings to dry. This characteristic posture makes the medium-sized water birds, which are excellent divers, very easy to spot.
Due to its undisturbed location (the island is closed to shipping) and the excellent interlocking of forest and water habitats, the island offers an excellent resting, breeding and roosting area for water birds. The birds find peace here all year round. Overall, the Gilberginsel is a nationally important stepping stone biotope and, together with the Ahauser Stausee about 6 km away, a valuable refuge for water birds.
During the winter months, volunteer ornithologists record the populations of water birds around the Bigge and Listersee lakes. If you would like to report your own observations or see who has made which observations, you can use the internet portals www.naturgucker.de or www.ornitho.de. The nature park's bird observation station on the Biggesee offers a very good opportunity to observe the water birds. The viewing point is located opposite the Gilberg islands and can be reached via the Biggerandweg. Well protected behind small peep windows, there is a particularly good chance of spotting starlings such as cormorants, grey herons, great crested grebes and the like around the Gilberginsel.
Please note: Gilberg Island must not be entered! There is also a no-entry zone for boats immediately around the island.