The blackbird (Turdus merula Linnaeus, 1758; Passeriformes, Turdidae) diet was studied to contribute to the conservation of the species population in transformed forests of the north-eastern part of Ukraine. Four forest ecosystems were studied: 3 model sites in the oak forests, transformed under intensive recreation pressure, and 1 model site in a pine-oak forest. A total of 44 invertebrate taxa, dominated by Insecta (78.1%, n = 1075), were found. The order Lepidoptera (63.5%) prevailed. In the diet of blackbird nestlings, the highest number of taxa (37.1–52.2%) was represented by phytophages. The phytophagous species also constituted the majority of the consumed prey items (58.8–72.0%). Environmental conditions provided an important effect on the diet structure. The most favourable foraging conditions for the species were found in protected natural areas. According to the analysis, the blackbird foraging efficiency was similar in all the studied sites. The highest biodiversity indices were found in a protected area of Homilshanski Forests National Nature Park. Results of the research have indicated a crucial role of T. merula in the population management of potentially dangerous agricultural pests.
