Lutjewad is one of four crucial locations for spoonbills in the eastern Wadden Sea region

The findings offer an opportunity to refine and strengthen existing protection measures in one of Europe's most ecologically valuable coastal zones. Researchers from BirdEyes, the University of Groningen, the University of Amsterdam and the Royal Netherlands Institute for Sea Research (NIOZ) tracked the behaviour and movements of 31 spoonbills (Platalea leucorodia leucorodia) over a period of 11 years. For this purpose, they used GPS loggers with behavioural sensors. The research focused on birds breeding on Schiermonnikoog, one of the most important colonies in the eastern Wadden Sea area. 

Lutjewad is relatively peaceful

The team discovered that spoonbills spend a large part of the summer outside the strictly protected breeding grounds. They shift their use of space in clear and predictable phases. Especially after the breeding season, male and female spoonbills gather on the mudflats of Lutjewad to moult and prepare for their southward flight. “What makes Lutjewad so suitable seems to be the relatively peaceful environment: there is little human disturbance compared to the surrounding areas,” explains Mohamed Henriques, ecologist at University of Groningen. "That could quickly change with the plan to lay a new TenneT cable south of Schiermonnikoog. Our study provides a baseline measurement to monitor the impact of laying a high-voltage power line in an area where the birds are particularly vulnerable." 

Four key areas in a living landscape

The habitat of the spoonbill population of Schiermonnikoog covers an area of 94.6 square kilometers. Using dynamic 'Brownian Bridge Movement Models', the researchers identified four important summer zones for spoonbills. These are the areas around the breeding colonies and the Wadden Sea coast of Schiermonnikoog, the tidal channels between the island and the mainland, and parts of the freshwater lake Lauwersmeer. The results also showed that males and females use these areas differently, but ultimately come together in the post-breeding period. Migratory bird ecologist Theunis Piersma of NIOZ and the University of Groningen: “Our results show that spoonbills view the Wadden Sea region as a living landscape. They go to different zones for different needs at different times. This gives us a more complete picture of what protection could mean in the field.” 

Dynamic conservation strategies

Most of the identified areas – including Lutjewad – have already been designated as Natura 2000 protected areas, National Parks or UNESCO World Heritage Sites. The new research by BirdEyes shows that some of these zones, which are well protected on paper, could be managed even more specifically to reduce seasonal human disturbance. By tailoring conservation measures even better to the seasonal needs of spoonbills, new opportunities arise to increase the ecological resilience of the region. "Our findings show that protecting breeding colonies alone is not enough," says Piersma. "To truly support the full life cycle of these iconic waterbirds, we need conservation strategies that are as mobile and dynamic as the birds themselves."

More information