Kamil Kaczmarek
Ornis Polonica 2023, 64: 31–51
https://doi.org/10.12657/ornis.2023.1.3
Abstract: In order to determine whether Magpies Pica pica use dustbins as sources of readily available anthropogenic food, litter bins were observed in two housing estates in Poznań city (532,000 inhabitants; W Poland) between December 2021 and November 2022. Twice a month, 252 single baskets and 30 collective rubbish bins, consisting of several containers, were inspected. The total time of Magpies observation on single baskets exceeded only in two months 1% of the total observation time for this type of bins. The same indicator for collective baskets, generally available to the public, was usually above 10%. Each month Magpies were found mostly on 2–5 baskets. Observations revealed that the garbage cans were visited by single individuals or pairs of Magpies. No positive correlation was found between the number of trash bins or their quality, and the stability of the Magpie territory. Both the observation of baskets and additional data obtained as a result of observations of Magpies feeding on the food left by the inhabitants indicate, that in autumn and winter, the Hooded Crow Corvus cornix may be a food competitor for Magpies. The low overall level of observations suggests that anthropogenic food from trash bins does not serve as an important diet component for Magpies as it is generally believed, or that they use other sources of such type of food.
Keywords: anthropogenic food, food competition, Magpie, Pica pica
