To the breeding ecology of thrushes of the genus Turdus in the forest-steppe of European Russia (on the example of the Voronezh Nature Reserve)

The article analyzes the breeding success and ecological features of three species of thrushes (the Song Thrush Turdusphilomelos C.L. Brehm, 1831, the Redwing T iliacus Linnaeus, 1766, the Blackbird T merula Linnaeus, 1758) in the conditions of the Voronezh Nature Reserve, where there has been no economic activity for 100 years. The plant cover consists of pine, oak, aspen, birch and alder forests, but it doesn’t include the spruce Picea abies, which is important for the placement of blackbird nests. The overall breeding success, determined by the modified Mayfield method, in the Song Thrush is 27.9%, the Blackbird is 25.4%, and the Redwing is 40.3%. This is lower than in other parts of the range and is due to the frequent destruction of nests by numerous predators. Reproductive losses greatly increase in the years with a cold spring. The high age of the forest, the great species diversity of plants, the presence of many natural hollows, windbreaks, contribute to the diverse placement of nests in all species of birds, which reduces the pressure of predators. Before the foliage opens, thrushes build nests on broken tree trunks, in half-hollows and hollows, in dense interlacing branches or hop stems Humulus lupulus climbing along tree trunks at a low height from the ground. The blackbird uses hollows and half-hollows more often. The negative impact of predators is also offset by long breeding periods, from mid-April to the first decade of July, which allow repeated attempts at nesting. The Redwing protects the fledglings from enemies the most actively, which can also increase the breeding success.