ANALYSIS OF THE MALLARD DUCK POPULATION SIZE Anas platyrhynchos Linnaeus, 1758 (Aves: Anseriformes: Anatidae, Anathinae) IN THE URBAN PART OF THE MILJACKA RIVER WATERCOURSE

Species of the genus Anas Linnaeus, 1758 settle the entire area of Bosnia and Herzegovina. Seven species of this genus have so far been recorded, mostly on the natural lakes and artificial hydro-accumulations on the territory of Bosnia and Herzegovina. A few years ago, species from the Anas Linnaeus, 1758 genus began to settle intensively on the watercourses in the Sarajevo Valley. A significantly large number of birds from this genus were recorded on the river Miljacka, which represents the main watercourse of the Sarajevo Valley. Mallard ducks Anas platyrhynchos Linnaeus, 1758 were highest in recorded numbers. This species inhabits all three parts of the watercourse of the Miljacka River: higher, middle, and lower one. All three parts of the watercourse are specific in terms of water flow speed and anthropological influences. During the research, we collected data on the local population size of Anas platyrhynchos Linnaeus, 1758 on the Miljacka River workflow section from the locality "Babin Zub“ (Dariva) to the confluence into the Bosnia River in the Sarajevsko Polje. Data collected by counting are the first and only available data from this region. In addition to counting, during the research we also collected data on a ratio between the sexes (sex ratio) of local population of species Anas platyrhynchos Linnaeus, 1758. The presented data might be helpful in protecting the population of species Anas platyrhynchos Linnaeus, 1758, and its long-term survival on the Miljacka River, given the fact these birds (especially the males) represent true ornament to the only river (polluted by organic waste) in Sarajevo. Key words: wild duck, population, Miljacka River watercourse