Herman van Oosten (2024) On the breeding biology of Common Nightingales Luscinia megarhynchos in Dutch coastal dunes. LIMOSA 97 (3): 97-106.

The Common Nightingale is a common breeding bird in the calcareous coastal dunes of N2000 nature reserve Meijendel (1800 ha), northeast of The Hague. Here, more than 300 singing males are counted annually. Between 2019-21, I found 29 nests in three sub-sites (Fig. 1), in order to study laying date, clutch size, nest success, breeding habitat, nestling diet and provisioning frequency. Dates of first eggs were determined for 21 nests: 52% were laid in 5-9 May (Fig. 2; min-max 30 April-27 May). Clutch size (26 nests) was 5.0 (25x5 eggs, 1x4 eggs, the latter being a replacement clutch, including one very small egg, Pic. 1). Out of 29 nests, 18 were successful (62%), the other 11 were most likely depredated. Nests were built mostly on the ground (N=11) or at most 30 cm above the ground (N=12) 6 nests were built at 50-100 cm above ground, mostly in Nettles (Tab. 1). Nesting sites were dominated by different shrub and tree species, mostly Hawthorn (Tab. 2). Nests were often built at at most 1 m from the shrub edge (17 out of 29 nests), but also deeper inside the quite open shrubs (7 nests 1-10 m from edge, 3 nests 10-20 m and 2 nests 20-30 m). Nestling diet was determined by filming feeding parents at 9 nests during 28 May-11 June. Per nest 191 ± 55 prey items were identified and the age of filmed nestlings was 7.9 ± 1.5 days (min-max 7-11 days, day 1=hatching). Depending on date and sub-site (the presence of water bodies), nestlings were fed with a variety of invertebrates (Tab. 3, Appendix 1), mostly caterpillars (30 ± 23%), imagoes of beetles (29 ± 24%) and dipterans (14 ± 14%). In a few nests, a lot of dragonflies were provided, up to 32% of prey, but not in the dry sub-site. Nestlings were fed 3.1 ± 0.7 times per nestling per hour.

[pdf only for members] [dutch summary]