Phenology of the Amur region tits superspecies Parus major in the context of their relationships in the zone of sympatry and hybridization

The paper considers the phenological parameters of the great tit (Parus major) and Japanese tit (Parus minor) in Priamurye. In the cohabitation zone of these species, there are places where pronounced hybridization occurs and the areas where it fades and stabilizes. This leads to the zone of sympatry subdivision into three main parts: western, central, and eastern. To understand the phenomenon of hybridization in these parts, its changes and differences, the phenological parameters of the eastern tit were studied and compared with those of the great tit. For the Japanese tit, the author has determined the dates of pre-spring migrations, flight and appearance at nesting sites, spring singing of males, the period of courtship and struggle for females, nest construction and egg laying, incubation of clutches, the appearance of chicks and fledglings, late broods, and also autumn migrations. It is given the data on this species wintering in Priamurye. The same indicators are compared with those for the great tit. It is revealed that the great tit males begin to sing early - from the end of December to the beginning of January, still in wintering groups. The aspects of behavior preceding direct reproduction: courtship of males for females, struggle between males for females, begging for food from males by females in already established pairs, are also manifested in great tits in wintering groups when there is not yet the Japanese tit main population at breeding sites. The spring flight and mass appearance of the Japanese tit at nesting sites occurs since March, and pairs form in nesting sites in April. However, the indicators of direct reproduction in these species coincide in time.