Sparrowhawks did not breed on Bardsey this year, so where did this bird come from? British Sparrowhawks are sedentary and most juveniles settle in an area after a short dispersal which is typically completed within four weeks of independence. Territorial Sparrowhawks have varying sizes of foraging range depending on factors such as season, sex and age. A study in Scotland found a juvenile female in winter would range up to 7km from its roost site. In comparison an adult male in early spring could range as little as 10 hectares. Northern European Sparrowhawks are however migratory. Ringing recoveries show that most winter visitors to Britain come from Norway and Denmark. A passage of these continental birds is observed annually on the East Coast but ringing recoveries have also occurred on the West and in Ireland. It is thought that the majority are birds heading to wintering grounds on the nearby continent. So a wandering resident or a Norwegian migrant? Now it has a ring we might at least find out where it's going and how long it stays here munching Blackbirds. (c) Richard Brown
Saturday, November 19, 2011
Although a Goldeneye, a Little Auk, a probable Water Pipit and a Snow Bunting have all been noted in the last few days, there is generally a quiet feeling to the island at the moment, as if things are keeping their heads down. With at least three Sparrowhawks working the island it's no surprise really. When trying to catch the Sparrowhawks we've had multiple near misses, with birds bouncing out of mist nets and escaping from the Heligoland. We were starting to think that this species would not be ringed in 2011, despite its status as a common migrant and with 105 ringed previously on Bardsey. Luckily however, Giselle managed to catch a juvenile male in the Heligoland Trap today, as it flew in hot pursuit of a tail-less Blackbird. The Blackbird got away.
Posted by Rich and Giselle at 10:29 AM