Natale dispersie van een vrouw Sperwer Accipiter nisus

Bijlsma R.G. 2024. Natal dispersal of a female Sparrowhawk Accipiter nisus. De Takkeling 32: 260-263. A Sparrowhawk’s nest in the Forestry of Smilde (Dieverzand) contained 4 chicks (5-7 days old) and 1 failed egg on 27 June 2024; the female must have been present (alarm call of passerines, otherwise silent) and in her first-year (as evident from the moulted feathers). A dead adult female Sparrowhawk was present underneath the nest, apparently having died this spring and decayed without any indication of predation of scavenging. She had been ringed and colour-ringed as a nestling in 2021, in Groningen some 45 km north of her breeding site in Drenthe. Moulted feathers found at the breeding site in Dieverzand in 2022 showed that the local breeding female had been in her first year of life. A comparison of feathers in 2023 and 2024 suggested that the same adult was involved. It is likely that the bird in Dieverzand had settled in her first year of life (in 2022), some 45 km away from her natal site. Her cause of death in 2024 remained a mystery (avian flu perhaps, given her position and condition under the nest). Her nest was possibly ‘usurped’ the same year by a first-year female, which laid a clutch of five eggs (start 12 May) and successfully raised at least 3 chicks.