Polish expert on the Bittern visited Cerknica Lake
Between 10 and 16 April 2018 we were visited by Dr Marcin Polak, one of the leading European experts on the ecology of the Bittern from the Maria Curie-Sklodowska University in Lublin, Poland. We invited him due to his rich experience with capturing this species. We hoped his experience would help us find the Bittern’s nest on Cerknica Lake, capture one specimen, and equip it with a GPS tracking device. Unfortunately, due to high water levels on the lake, we were forced to change our original plans.
During his stay by Cerknica Lake, Dr Marcin prepared an in-depth lecture on the ecology of the Bittern, with special emphasis on the information which will be relevant to our attempt to capture the bird – when and how to survey the drumming males, where to search for the female’s nest, and how to set up mist nets. In addition, he offered a number of concrete solutions on how to create the Bittern’s habitat in the planned quiet zone, so the species has the optimal food and nesting conditions. The representatives of Notranjska Regional Park, the Institute of the Republic of Slovenia for Nature Conservation, and DOPPS – Birdlife Slovenia attended the lecture. Afterwards, we took Dr Marcin on a tour of the lake, where we showed him the viewpoint at “Levišča” and the location of the planned quiet zone for the Bittern. We explained the hydrology of the area to him.
Field visits to the lake were only possible from its periphery, so Marcin spent every evening of his stay on different points along the coast and listened for the Bittern to see whether the males have returned despite the exceptionally high water levels. Unfortunately, the results weren’t encouraging. Still, he encouraged us that we don’t need to completely lose hope for this year, since in Italy, for example, Bitterns nest up to one month later than elsewhere in Europe. A week later, we in fact heard the drumming of the first male, which we will monitor carefully in the following weeks. It needs to stay in the area for at least 2 to 3 weeks, before we can start searching for nests. Our goal is to equip a nesting female with a GPS tracker.