Composition and Ecological-Geographical Differentiation of Rare Bird Species in the North of the Central Siberian Plateau

Abstract— The role of rare bird species in the avifauna of the northern Central Siberian Plateau is analyzed using the Putorana Plateau as an example. The route census method was used. From 1958 to 2023, 172 encounters of 64 rare and vagrant species were recorded at 21 locations on the Putorana Plateau. The locations ranged from 100 to 1900 km from the known northern boundaries of their ranges, with an average distance (n = 58) of 600 km. Vagrant bird visits by 25 species are also known north of the Putorana Plateau—in the forest-tundra and tundra of Taimyr and the Anabar Plateau. Passeriformes and Charadriiformes predominate by number of species, together accounting for 58%. The vast majority of encounters were recorded from June 1 to August 31. The most significant are widespread and boreal species, together accounting for 74%. The role of boreal-hypoarctic, nemoral, nemoral-steppe, forest-forest-steppe, steppe-forest-steppe and alpine species is secondary, their combined share being 26%. Of the species found outside the known boundaries of their nesting ranges, 1‒13 encounters were recorded, with an average of 3 (n = 64). Species were recorded at 1–9, with an average of 3 (n = 64) points. At various points on the Putorana Plateau, 1–17 species were noted, with an average of 7 (n = 21), and 1–21, with an average of 8 (n = 21) registrations, were recorded. The number of rare and vagrant species decreases from west to east by 2. 2 times, while the number of their registrations decreases by 2,5 times. In the western half of the region, the number of rare and vagrant species decreases by a factor of five from south to north, while the number of their registrations decreases by a factor of four. Bird stopovers are an integral component of the formation of biodiversity in the mountainous regions of the northern Central Siberia and the transformation of avifauna in the face of environmental change.