KLEEFSTRA R, H HORN, M LEOPOLD & O OVERDIJK (2009) Little Egrets Egretta garzetta in the Dutch wadden sea: from Mediterenean rarity to typical Dutch shorebird. LIMOSA 82 (3): 158-170.

Following the increase and range expansion of Little Egrets in NW-Europe in the 1990's the species became an occasional breeder in The Netherlands in 1994. In 1999 Little Egrets also started to breed annually on islands in the Dutch Wadden Sea (2 pairs), after a first unsuccessful attempt in 1995. The number of breeding pairs increased to 27-29 in 2008 (Fig. 1). Until the late eighties just a few individuals were seen annually in the Dutch Wadden Sea, mainly in spring and summer. In the 1990s the number of non-breeding Little Egrets increased in late summer with peak numbers in August (Fig. 3,5). After the species started to breed, a shift in the seasonal distribution occurred, and nowadays peak numbers are recorded in September (>100 in 2006; Fig. 6) and the wintering population is increasing (>30 in January 2007). These changes in seasonal occurrence were also observed elsewhere in NW-Europe (W-France, S-England). A further increase and range expansion of Little Egrets in the Wadden Sea is to be expected. New breeding sites were already found on the islands of Ameland and Zuiderduin and the German island of Memmert in 2007 and 2008.
      On the Wadden Sea islands Little Egrets breed on the ground in saltmarshes and low dunescapes in mixed colonies, mainly consisting of Spoonbills Platalea leucorodia, European Herring Gulls Larus argentatus and Lesser Black-backed Gulls L. graelsii. In the main colonies the mean clutch size varied from 3.0-5.0 (Terschelling, 2001-2008) and 3.0-3.9 (Schier monnikoog, 2002-2008; Tab. 1). On Schiermonnikoog the median laying date of first eggs was 20 May. Since the first breeding attempt 101-108 breeding pairs have been registered on the Dutch isles up till 2008, fledging at least 114-116 young. Mean breeding productivity in 1999-2008 was 2.1 (range 1.0-3.5) fledged young per pair on Terschelling, and 1.1 (range 0.5-3.0) on Schier monnikoog. 75 nestlings have been colour-ringed in the Dutch Wadden Sea. Winter reports (N=12) came from France, Spain, the UK and Hun - gary, but most (63%) from the Delta area in the southwest of The Netherlands and from the Wadden Sea itself.
      Prey remains show that Little Egrets mainly feed on marine animals that are common in shallow water and creeks in and near salt marshes. Based on mass Whiting Merlangius merlangus was the main prey of an adult Little Egret, while Flounder Platichthys flesus formed the main prey of young.

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