Influence of seasonal climatic factors on the dynamics of birds interactions with oaks consortia
Authors: Ponomarenko O. L. , Shulman M. V. 
Published: February 2020

The article is devoted to the bird communities in individual oak consortia (Quercus robur L.) of the linden-ash oak forests. This work material was collected during different seasons of the 2004–2010 years in a linden-ash oak grove on the test plot No. 209 of the ecological profile of the NSC «Bel'gard Prisamar`e International Biospheric stationary», Novomoskovsk district, Dnepropetrovsk region. The individual consortia of 281 examples of three age conditions oak trees (virgins – virg, young generative – gl, mature and old generative individuals – g2–g3) has been investigated. The daily time budget decreases by 2–2,5 times in autumn for all oak ages that have been studied. But the number of consort birds is reduced by 2 times only for virgin and old generative oaks. The young generative oak is attractive enough for birds in autumn. The ratio of the trophic and topical share interactions for all trees ages does not change significantly in autumn. Birds don’t interact with the virgin oak in winter practically. This age oak can’t propose enough food or places for birds’ protection from predators. Oaks in age g1–g3, on the contrary, are in demand by the birds. There 7 birds species on g1 oaks and 13 species on g2–g3 oaks were recorded in winter. The birds’ daily time buds for the one oak example are low in winter, and by the 90 times reduce compared with the summer. The bird time budget basis in winter are the trophic interactions. The birds’ activity on oak sharply increases in spring and exceeds 1,5–2 times the summer parameters on virgin and mature generative oak (g2–g3). Birds on oak spend most of their time on topical interactions during this season because of the oak important role in the birds reproduction. On the other hand, the young generative oak (g1) is not in demand by the birds in spring because of insufficient crown density and the oaks of this age location at the edge. The number of bird species on oak in spring is less than in summer due to the late onset of leaf blooming on the oak. A significant part of the birds’ activity in the spring moves to the lower tier of the forest because of the earlier vegetation beginning. As a result of the research, it was revealed that the consorting groups of common oak throughout the year retain the main features of their organization. The virgin oak is characterized by a stochastic nature of the birds interaction with the consortium core and almost hasn’t obligate consort birds. Young generative oak is actively forming a trophic relations system with consorts due to intensive linear growth. At this age, first of all, general indicators are formed – time and mass budgets. The consortium of mature and old generative oak has a significantly larger number of bird species consorts and their interactions diversity with the tree. This can help to increase the stability of consorting groups. In most cases in the oak consortium the trophic component of the consortium form earlier then the topical. The specific location of the virgin and young generative oak at the lit positions in the lime-ash oak forests influences the oak consortia formation in a considerable scale. The number of types of interactions between the consort and the autotroph is the most effective indicator, which shows a high level of the consortium development. The stability of consortial relations between birds and English oak grows throughout the year from virgin oak to mature and old generative. The virgin oak unstable consorting groups have fluctuations of the species number during the year up to 100 % (the number of consort species in summer was chosen as the initial value). The consortia species composition fluctuations reach 81,82 % for young generative oak, and 59,26 % – for mature and old generative oak. The mature and old generative oak consortia attract seasonal bird species that replace each other throughout the year more actively. This ensures the stability of year-round control of phytophage populations.