The summer 2020 at the Observatory
This year, the bird observatory staff have not been able to provide regular diary updates on the website due to the extensive workload associated with our various bird research projects. Instead, here is a summary of the summer months.
June marked the end of an intensive spring season involving a large number of projects. Despite a cold spring and early summer, we captured many juvenile birds. Studies of farmland species were expanded to include intensive monitoring of species such as the Eurasian Skylark. The vulnerable Ortolan Bunting population continues to be monitored. This year also saw the completion of the crow survey, which is conducted every five years. We identified 35 breeding pairs of Hooded Crows and four breeding pairs of Ravens. This indicates that the crow population in Kvismaren has remained relatively stable over the past twenty years, with a slight increase since the previous survey in 2015. This contrasts with the Swedish Species Information Centre’s recent classification of the crow as Near Threatened (NT).
Wetland surveys were carried out according to our standard procedures. Both Little Gulls and Black Terns bred in the area, but although many Little Gulls were present during May, only five pairs nested. This year we attempted to protect them from predation by installing a fence around the nesting area, a measure implemented by the County Administrative Board. The effort appears to have been successful, as several fledged young were observed.
During the spring and summer, we experienced serious leakage problems in the water-control structures. Maintaining proper water levels is essential, and we will discuss possible improvements with the County Administrative Board.
Sörbysjön was once again highly productive, supporting a large colony of Black-headed Gulls. There was also a large colony in Rysjön, but it was abandoned when leakage caused the area to dry out. On a positive note, Tufted Ducks bred successfully for the first time in several years.
Despite the COVID-19 pandemic, we were fortunate to recruit skilled staff who remained with us for an extended period. Although the limited number of personnel required us to scale back some projects, we were able to carry out most of our planned work successfully.
Bird Ringing
The Starling project had an average year, with 161 nestlings ringed in nest boxes. The expansion of Savi’s Warbler in Kvismaren continues; in addition to one ringed brood, seventeen juvenile birds were ringed, giving a total of 24 Savi’s Warblers.
Standardized bird ringing began on 22 June. By 14 August, 2,306 birds had been ringed through the standard programme. In addition, staff working on the Great Reed Warbler project conducted trapping in the lakes and ringed all non-target species captured as bycatch, as they have done in recent years. This additional effort resulted in 1,574 birds being ringed. Among the most frequently captured species were 1,243 Eurasian Reed Warblers, 1,004 Sedge Warblers, and 341 Willow Warblers. Less common captures included one Common Kingfisher, one Common Rosefinch, and two juvenile Blyth’s Reed Warblers, strongly suggesting local breeding.
By 14 August, approximately 4,300 birds had been ringed in total, a high figure and slightly above last year’s total. We hope the autumn season will continue to produce good catches and, ideally, some exciting bird observations in the area.