De Sperwer Accipiter nisus als broedvogel in de provincie Groningen in 2013

The Sparrowhawk survey in the province of Groningen of 2012 was continued in 2013, partly by replicating the previous survey, and partly by investigating municipalities not yet surveyed. Respectively 35 and 38 territories were located in 2012-13, of which 13 in 2013 had not been located before. Of 34 pairs closely tracked in 2013, 21 were successful in raising at least one fledgling (62%, similar to the 63% in 2012). Predation of nestlings is quite common. The majority of nests was built in a wide variety of deciduous trees (22x, i.e. in Quercus robur, Acer campestre, Salix sp., Populus sp., Betula pubescens, Fraxinus excelsior, Prunus padus and Crataegus monogyna), less often in coniferous trees (12x, mostly Picea abies and Pinus sylvestris, but also Pseudotsuga menziesii). Checking plucking posts for pellets and with a metal detector proved to be a fruitful enterprise when finding rings is considered, with three juvenile tits (Parus major and Cyanistes caeruleus) and two juvenile Barn Swallows Hirundo rustica from ringing sites within 1 km of the Sparrowhawk eyrie, and a Belgian ringed bird (details not yet known).