Groeicurves van nestjongen van enkele zangvogelsoorten

During 1995, single nests of Tree Pipit, Redstart, Garden Warbler and Linnet, two nests of Spotted Flycatcher and three nests of Pied Flycatcher were checked daily to measure wing length (maximum wing chord) and body mass (to the nearest 0.1 g, with a digital balance)(Appendix 1). Moreover, the days at which the eyes opened and primaries started to protrude from the blood shafts were recorded (Table 1), because these dates indicate a significant change in behaviour. Nestlings with their eyes open and with protruding primaries are prone to leave the nest prematurely, the nightmare of every nest searcher.