LIFE TRŠCA: Ferruginous Duck Ducklings Observed?

In Levišča, two birds were observed that closely resemble ducklings of the Ferruginous Duck. If this turns out to be confirmed, it would be remarkable news, as no ducklings of this species have been seen for more than 30 years. On the other hand, this is not unusual, since the juveniles are very small, hide in the reeds, and are almost impossible to spot. An additional complicating factor is that it is very difficult to distinguish young birds from females in summer. Ducklings are small and therefore more recognizable, but they quickly reach the size of adult birds and have similar coloration. For reliable identification, good lighting conditions and knowledge of the species’ phenology are therefore essential. Thus, the photo shows two female Ferruginous Ducks, which could easily be mistaken for juveniles, but unfortunately we will have to wait another year for such an observation to be confirmed.

For nesting, the Ferruginous Duck requires relatively shallow water up to 1 meter deep and enough tall aquatic vegetation in which it can hide its nest. Because the water level of Lake Cerknica fluctuates, nesting conditions are very demanding. However, the combination of this year’s long period of relatively high water levels and the reduced extent of reed mowing last year undoubtedly creates better nesting conditions.

The Ferruginous Duck is a critically endangered breeding species in Slovenia. It is a regular breeder at Lake Cerknica, where 1–5 pairs nest, and Lake Cerknica is also its only breeding site on a natural water body in the country. This year as well, up to four pairs of this species are present at the lake.

As part of the project, we will monitor this species more closely and try to provide it with the best possible breeding conditions. If you have spotted it too, please share this information with us.

The article was updated on 9 December 2025.