Vervolging van roofvogels in Nederland in 2011

Poisoning (N=16) and deliberate disturbances of nests (N=93) were recorded throughout The Netherlands (Table 1). Victims of poisoning were Buzzard Buteo buteo (N=10), Goshawk Accipter gentilis (N=5) and Marsh Harrier Circus aeruginosus (N=1). Raptors were poisoned with aldicarb (3x), and in poisoned baits aldicarb (2x), carbofuran (2x) and parathion (3x) were identified. Pesticide concentrations were found of up to 45,000 mg/kg (aldicarb in a Woodpigeon Columba palumbus, used as bait). The baits used for poisoning raptors are typically hunter’s quarry, i.e. pigeons (10x), and whatever is available (chickens, chicken eggs, Mole Talpa europaea). Nest disturbance is widespread and involves a large variety of methods: deliberately keeping parents away from the nest (farming activities, placing a hide near the nest, cutting down tree near nest, and so on), destroying eggs, killing nestlings, cutting down the nesting tree, shooting nests, shooting parents (at the nest, or away from the nest). Based on the recorded intensity of nest-related persecution (Table 2), the large sample of nest record cards (3102 in 2011, all species), the wide distribution of nest record cards across the country and recent population estimates of raptor species, it is calculated that a minimum of 732 raptor nests must have been destroyed in 2011, distributed among Buzzards (430), Kestrels (120), Goshawks (74), Marsh Harriers (64), Honey-buzzards (18), Sparrowhawks (18) and Hobbies (8). This is a minimum, as many nest failures cannot be proven as caused by deliberate disturbance, despite being recorded in areas with a high incidence of illegal persecution. By far the highest frequency of killing and nest disturbance is observed in the province of Friesland, where the conservationists of meadow birds believe that killing raptors and other predators will stop – or even reverse – the long-term decline of Black-tailed Godwits and Lapwings.