Broedende Grote Lijsters Turdus viscivorus in Boswachterij Gees in 2000

In 2000, 16 territories of Mistle Thrushes were located in the Forestry of Gees in Drenthe (721 ha, 83% woodland). Territories and nests were situated in proximity of woodland edges (Fig. 1), presumably in response to favoured foraging sites (fallow, fields and recreation sites). Nest site choice was diverse, with mean nesting height of 7.2 m (SD=2.79 ). Six out of nine nests were successful. Most clutches started in the first week of May (Table 1). The relatively late onset of laying contrasts with country-wide collected data (1996-99, n=26, most started in April, 2 in March) and information from the first four decades of the 20th century (mostly April, with first pairs always in last decade of March). However, given the warmer springs in the 1990s, retarded laying is unlikely in the late 20th century. The scarcity of layings from March in the 1990s is probably observer-biased.