Grondnest van Slechtvalk Falco peregrinus op de Hoge Platen in 2006

In 2006, a pair of Peregrine Falcons Falco peregrinus successfully raised a chick in a ground nest on the Hoge Platen in the province of Zeeland. This sandbar and mudflat in the estuary of the Scheldt river is surrounded by tidal streams and covers some 1800 ha during low tide. During spring tide, a small part of 60 ha is not flooded. Some sand dunes have been formed in recent years, partly overgrown with vegetation. In this vegetation, close to a sand cliff, the nest was situated (Photo 1). It was found on 30 June, and held a single chick (Photo 2). The male chick was ringed on 7 July, when its wing length measured 223 mm (flattened and straightened) and its mass was 604 g (no crop). Its age was estimated at 32 days, and breeding was back-calculated to have started on 3 May. On 13 July, when 38 days old, it was observed wing-practising. Prey remains found in the vicinity of the nest (7 and 20 July) were from Racing Pigeons Columba livia (17, of which 1x Great Britain, 1x Germany, 2x France and 7x The Netherlands; ages were 5x first-year, 2x second-year and 4x third-year), 9 Starlings Sturnus vulgaris (1 adult, 8 juveniles), 8 Redshanks Tringa totanus (3 adults, 5 juveniles) and 1 Avocet Avosetta recurvirostra (small chick). The adult Peregrines were quite tolerant towards human disturbance, with recreation and other human activities some 800 m away on the water or along the shore. The adults approached the nest in a stealthy, low flight which did not even disturb the nearby nesting 50 Common Tern Sterna hirundo pairs. The sandbar has been a wintering site of Peregrines for decades. In recent years, numbers have increased, presumably following the settlement of pairs in the vicinity. In The Netherlands, breeding on the ground has been recorded twice before, i.e. in 1926 and 1930 on Dutch Wadden Sea Islands. Since 1999, ground nesting is also recorded on the German Wadden Sea Island of Trischen.