Opmerkelijke oogst van geringde prooien bij inspectie van een haviksnest Accipiter gentilis na de broedtijd

On 24 July 2016, a Goshawk nest in Groningen was checked after fledging. The nest had been occupied in 2015 and 2016, both times successfully (3 chicks ringed in 2016). The ground underneath the nest was searched with a metal detector, the nest itself with a pinpointer (Deteknix), to locate metal rings. This took about 45 minutes. Altogether, 9 metal rings, 4 colour rings, 5 transponders and 1 ring of a German racing pigeon Columba livia were found. Two of the metal rings referred to Sparrowhawk Accipiter nisus chicks that had been ringed on 12 June 2016, on a nest some 400 m away. All other rings and all transponders belonged to Jackdaws Coleus monedula, mostly juveniles but also at least one adult, that were part of several colonies under study by scientists of the University of Groningen. It shows that using a metal detector or pinpointer at raptor nests can be worthwhile and time-effective. The pinpointer, however, turned out to be less effective when steel rings were involved (https://youtube. com.watch?v=sgj6ohixWqQ).