De roofvogels van Rottumerplaat in 2019

The island of Rottumerplaat in the eastern part of the Dutch Wadden Sea covers some 800 ha and is only sparsely vegetated. The island was surveyed in summer 2019 when three raptor species were recorded as breeding birds, i.e. Marsh Harrier Circus areuginosus, Buzzard Buteo buteo and Peregrine Falcon Falco peregrinus. (In 1993 and 1994, a Hen Harrier C. cyaneus pair had been breeding on the island, but not since then.) Marsh Harriers were first recorded as breeding bird in 1995, with 2-6 pairs in 2002-19. Of the three pairs in 2019, two were successful and raised a total of 8 fledglings. Three Buzzard nests were located in low trees, between 818 and 1600 m apart. One nest with three eggs resulted in one fledgling, although the nest was destroyed by high winds. Two other nests, each with two eggs, failed. Buzzards colonized the island in 2009, with a single pair in 2009-13 (uncertain for 2011), and respectively 2, 3, 2, 2, 2 and 3 pairs in 2014-19. Two Peregrine pairs were located, 1900 m apart and nesting on the ground, with respectively 3 and 1 egg(s). The latter failed to hatch. The first nest raised two fledglings. Peregrines have been present as breeding birds since 2005: one pair in 2005-11 (annually raising 2-4 chicks), absent in 2012-14, again breeding with a single pair in 2015-18 (1-3 chicks annually). The prey list (n=53) for 2019 showed mostly racing pigeons Columba livia and waders. As passage migrants or temporary residents, an array of other raptor species were recorded, i.e. Sparrowhawks Accipiter nisus, Goshawk A. gentilis (a first-year on 2-3 July), Hen Harriers (at least 16 between 17 and 25 April), Ospreys Pandion haliaetus (single birds on 15 and 22 April), White-tailed Eagles Haliaeetus albicilla (including two first-years and 1 third-year on 1 April, scavenging on dead seal), Rough-legged Buzzard Buteo lagopus (1 bird on 11-12 April), Kestrel Falco tinnunculus (recorded on 22 out of 122 observation days, with up to 5 on 24 April; the island has no voles or mice to offer) and Merlin F. columbarius (observed on 13 days between 31 March and 25 April, with up to 3 birds on 24 April).