VAN OOSTEN H (2022) Notes on the breeding biology of Bluethroats Luscinia svecica in Dutch coastal dunes. LIMOSA 95 (2): 80-88.

Bluethroats are common breeding birds in the Netherlands and over large parts of Europe. Yet, their breeding biology is not well known, which perhaps especially applies to nestling diets. I describe the breeding behaviour of a female by using a thermistor probe placed in the nest cup, as well as the diet of young in two nests near Castricum, as established by close-up filming feeding parents at the nests. The female took her first breeding break of the day 39 min before sunrise, on average and her last break of the day 25 min after sunset (Tab. 3). She was on the nest for 15 ± 7 min, off the nest for 5 ± 2 min and took 46 ± 9 breeding breaks per day. All in all she was on the nest 82% per 24 hrs (Tab. 3). Nestlings were fed to a large extent with larval click-beetles (72 and 48% per nest; Fig. 3, Tab. 4) and with noctuid caterpillars (15 and 31% per nest; Fig. 3 and Tab. 4). The two broods were fed 14.5 and 18.7 times per hour (3.1 respectively 3.6 times per young), which is similar to the co-occurring Meadow Pipit and Stonechat.

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