Lepelaars Platalea leucorodia in De Onlanden in 2017-22

Numbers of non-breeding Spoonbills in the shallow marshes of the recently created wetland of De Onlanden (3000 ha) in the northern part of the province of Drenthe showed a steady increase in the period of 2017-22, after initially low numbers in 2008-16. Roosting Spoonbills were counted twice a week between April and October. Numbers were very low in April-May, and increased from June onwards to a maximum in September. Systematic leg-scanning showed that 9.4% out of 7396 Spoonbills carried a coded colour-ring. Using the ratio ringed versus non-ringed individuals, the maximum local population has been calculated at 498 individuals, i.e. many more than separate counts had revealed. Colour-ringed Spoonbills indicated that most birds in June, July and August originated from breeding colonies on Wadden Sea Islands. These birds stayed in De Onlanden for several weeks to months. Many Spoonbills visiting the area in September originated from the German Wadden Sea and the western coast of Denmark; these late summer visits lasted only a few days or a week at most, before the birds continued their southward migration.