The results of long-term monitoring of the abundance of the raven (Corvus corax L., 1758) in the forest parks of Moscow and the Moscow region

Aim. To determine the number and density of populations of the raven ( Corvus corax ) in Moscow and the Moscow region based on the results of monitoring in the period 2006–2024. The method of route accounting was used without limiting the detection band with the calculation of population density based on the average detection ranges of birds. The status of the species was determined on the basis of population density estimates (individuals per km 2 ) on the A.P. Kuzyakin scale. Accounting routes were laid through the territory of the forest park area in the Istra district of the Moscow region, in the Ulyanovsk and Valuevsky forest parks of Moscow, the Mytischinsky forest Park of the Losiny Ostrov National Park of Mytishchi, the Losinoostrovsky Forest Park of the Losiny Ostrov National Park of Moscow and in the Pirogovsky Forest Park of Mytishchi during the period 2006–2024. In the Ulyanovsk and Valuevsky forest parks, the raven belonged to the category of rare and very rare species, respectively, from the very beginning of monitoring and gradually ceased to occur, which may be explained by an increase in the intensity of anthropogenic processes after the territory became part of New Moscow in 2012. In Losinoostrovsky and Mytishchi forest parks, the raven was initially a common and rare species, respectively, but after 2021, its number decreased sharply. In the Pirogov Forest Park, the raven was a common species until 2018, when a highway began to be built through the territory of the forest park, which led to the transition of C. corax to the rare category. During the research period, there was a decrease in the number of raven populations in the Moscow region, which is most likely due to an increase in anthropogenic pressure.