RODER FE DE,NAP J & BIJLSMA RG (1994) Tree-nesting raptors in Noordoostpolder and Oostelijk Flevoland in 1989 - 1993. LIMOSA 67 (2): 41-44.

The :aptor population breeding in forests in the newly reclmmed polders of Noordoostpolder (reclaimed in 1943, planting of forests in 1947-55) and Oostelijk Flevoland (1957, planting in 1958-68) was studied during 1989-93. Common Buzzard and Goshawk colonised the ~oordoostpolderin 1969 and 1981, Oostelijk Flevoland III 1980 and 1983-84, respectively. At present, the raptor population in both polders (6920 ha of woodland) consists of Honey Buzzards (8 pairs), Goshawks (52), Sparrowhawks (42), Common Buzzards (100) and Hobbies (10). The Kestrel population, virtually confined to nestboxes in farmland, is estimated at 120 pairs. Most Goshawks, Sparrowhawks, Common Buzzards and Kestrels, ringed as nestling, were recovered within 40 km of the ringing site, viz. within the confines of the polders. The colonisation of the polder forests is thought to have been originated from breeding areas in the eastern part of The Netherlands, whereas the subsequent rapid population growth resulted from local reproduction (table I). Eurasian Sparrowhawk Accipiter nisus Northern Goshawk Accipiter gentilis Common Buzzard Buteo buteo

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