Opmerkelijke observaties bij een haviksnest Accipiter gentilis in de herfst en winter

A Goshawk nest that had fledged two chicks in 2022 was outfitted with a camera trap on 3 September 2022, in order to register activities at the nest during autumn and winter. The Reconyx Hyperfire 2 was placed on a branch within one metre of the nest, and accepted by the Goshawks. Each movement at the nest was registered with one camera shot followed by 10 sec of film. Throughout the period between September and March, four different Goshawks were active at the nest (the local pair and two ‘strangers’), bringing nesting material (a fresh twig already on 4 September), inspecting the nest cup, building and rearranging nesting material, calling, flagging undertail coverts and attacking prospecting Egyptian Geese Alopochen aeygyptiaca standing on the nest. Copulations were not recorded on the nest, and simultaneous nest visiting by male and female was rare. The frequency of visiting increased in the course of the winter, and was highest in February and March (first egg laid on 29 March, at 18:45 in the evening). Visiting already started at sunrise and continued throughout the day though rarely at sunset. In line with increasing day length during winter, nest visits eventually covered >10 h per day in March, compared to 2-7 h per day in February. The female was responsible for 53% of the visits in February, but in March the male was more often seen on the nest. A large variety of other species were registered as visitors to the nest, ranging from Great Tit Parus major (23x) to Blue Tit Cyanistes caeruleus (9x), Tawny Owl Strix aluco (3x), Great Spotted Woodpecker Dendrocopos major (3x), Nuthatch Sitta europaea (2x), Short-toed Treecreeper Certhia brachydactyla (1x), Blackbird Turdus merula (1x) and Woodpigeon Columba palumbus (1x). Three visits of an Egyptian Goose were clearly intended as nest take-over and the furious reaction of one of the Goshawks (once with physical attack) showed that it was perceived as such by the owners of the nest. Among mammals, nest visits were recorded for Stone Marten Martes foina (9x ) and Red Squirrel Sciurus vulgaris (2x). If anything, the images proved that a raptor nest, in this case of a Goshawk, is year-round in use by the owners, and a magnet to other birds (twice including Goshawks other than the resident pair, referring to an unbanded juvenile of unknown sex and a ringed juvenile female) and mammals. Nest protection throughout the year is therefore important.