Фенологические явления в системе биоиндикации климатических трендов
The dynamics of the dates of the onset of phenological events such as the arrival of starlings (Sturnus vulgaris L.), the first cuckoo song (Cuculus canorus), the appearance of the first birch leaves (Betula verrucosa Ehrh.), the bird cherry (Padus racemosa Lam.) and the very early flowering of the rowan (Sorbus aucuparia L.) allows us to conclude that there is an increasing trend in the duration of spring, while the duration of the fall season for the period from 1967 to 2010 is practically unchanged. For the beginning of bird cherry flowering, the offset of the trend to earlier dates is more typical for the forest and forest-steppe territories of the Russian Plain, what suggests the connection between climatic parameters. For the appearance of the first birch leaves, the multi-directional trends of the offset of dates is obvious and revealed no dependence on natural conditions and physiographical position. The advanced arrival of starlings and the start of cuckoo song cannot be used as reliable indicators. No reaction to the unique weather conditions was demonstrated by birds. It is possible that the mechanisms of migration of birds are more likely caused by the presence or absence of prey and endogenous biological rhythms.