Population density and habitat preferences of the Collared Flycatcher (Ficedula albicolli TEMMINCK, 1815) in floodplain forests - A case study from the Donau-Auen National Park, Lower Austria
Waringer Barbara, University of Vienna (AT)
The Collared Flycatcher (Ficedula albicollis, Muscicapidae) is one of a few insectivorous long-distance migrants with a slightly positive population trend. In spring 2015, habitat use of a population in the floodplain forests of the Donau-Auen National Park, Lower Austria, was examined. The following questions were addressed: In which order are territories established? What are the most important factors for a high quality habitat for Collared Flycatchers in the Donau-Auen? Is early territory establishment related to a close distance to water bodies and a high insect density? Singing males were counted at 147 points in six survey rounds. Possible breeding competitors and cavity providers, cavities, deadwood, flying insects, vegetation- and landscape variables were assessed. A model selection approach identified important factors for territory presence. 57% of the census points contained territories resulting in a population density between 7.28 and 21.4 territories/10 ha. Canopy surface roughness proved being the best predictor. Established territories were found with higher likelihood at sites with higher canopy roughness. Territories with higher canopy roughness showed a tendency to earlier occupation. As forestry measures were stopped just 20 years ago and canopy roughness increases with stand age, the habitat quality of the remaining Danube floodplain forests east of Vienna for Collared Flycatchers will likely remain similar or could even increase in the mid to long term.