LIFE TRŠCA: Ferruginous duck

(photo: Jure Novak)

Ferruginous Duck Aythya nyroca is a rare, occasional breeder in Slovenia. The majority of the population breeds in the ponds on the Dravsko polje. It is also only an occasional breeder on Lake Cerknica, but occasionally it is recorded in large numbers, up to several hundred individuals, on migration. It prefers shallow but stable water with plenty of aquatic plants, the most common being common reed and bulrush. It is considered one of the critically endangered breeding birds in Slovenia, globally designated as NT (Near Threatened), and is one of the priority species for action under the European Commission's LIFE scheme and one of the protected species of the Natura 2000 site Lake Cerknica. The majority of its population breeds in Asia. It feeds on aquatic plants and, especially during the breeding season, on invertebrates.

Within LIFE Tršca, we will monitor its population and the response to the abandonment or reduction of reed cutting and other measures - using a modified transect method, boat and lake edge censuses, and drone and photo traps. Because of its secretive life, monitoring the Ferruginous Duck is a difficult task and different survey methods have to be combined. Each year we will write a report on its status on the lake. Volunteers will also help us to monitor Ferruginous Duck population, especially by telescope to monitor it from the edge of the lake.

Before any measures are taken, we will prepare an analysis of its ecological requirements, with the help of experts from abroad. In May this year, we have already hosted two professors from Poland - Marcin Polak and Janusz Kloskowski, who have also carried out an analysis of the food resources for the Ferruginous Duck. A key action in the project will be the creation of six open water 'eyes' in the middle of the reedbed, which are particularly suitable for the Ferruginous Duck. We are counting on the positive effects of the new agri-environmental measures to adapt the use of the reedbeds and to prescribe the use that is most suitable for the Ferruginous Duck. During the project, we will provide analyses and measures to limit disturbance to its breeding grounds, in particular visitor access with increased presence of wardens. Visitors will be directed away from the quiet zones for the Ferruginous Duck to areas where they will not disturb the nesting birds on the lake.

If you are going to observe Ferruginous Duck on the lake, we would like to mention a special feature. It is very easy to distinguish a male from a female, as males have a white pupil while females have a dark pupil. However, if you see a group of greyer specimens in June or July, please report this to the park as soon as possible, as they are probably juveniles.

The contribution was prepared by the Slovenian Society for the Observation and Study of Birds (DOPPS).