Influence of seasonal climatic factors on the dynamics of birds interactions with maples consortia

Abstract

The article is devoted to the bird communities in individual maple consortia (Acer campestre). This work material has been collected during different seasons of 2004‒2010 years in the linden-ash oak grove on the test plot No. 209 of NSC «Bel'gard Prisamar`e International Biospheric stationary» ecological profile, Novomoskovsk district, Dnepropetrovsk region. The individual consortia of 214 examples of three age conditions maple trees (virgins – virg, young generative – gl, mature and old generative individuals– g2–g3) has been investigated. Some bird species daily time budget (DTB) per autotroph exampl on average has been the basic parameter for the birds’ participation in the consortia functioning assessment. The maple consortia communities have been revealed in the result of investigation to be the basic for the oak birds. Non-forest birds species almost have not appeared in them, which differs them from the consortia of the oak forests edificators, for instance, oak. Field maple attracts birds in the cold seasons because of its participation in the forest stand formation and of its ontogenesis course. Field maple seeds remain on the tree during the autumn and winter and support the birds vital activity in this period, unlike oak. The total birds’ activity in the trees decreases significantly in the fall. But such situation is observed in autumn only on virg maple. Maples g1, g2–g3, on the contrary, attract birds in autumn more than in summer. There are more DTB birds on these maples in autumn than in summer, because of the late leaf falling and numerous fruits availability. Birds eat actively phytophages on maple fruits. The autumn community of wild maple birds aged g2–g3 is the most active on DTB index. On the other hand, the species composition on generative maples decreases two to three times in comparison with summer. In winter the birds DTB activity on maple decreases by 15–20 times, because of the wintering birds migration to the settlements. Very few birds remain in the oak forest in winter. But the birds wintering in the oak forest species composition is quite diverse, which affects the birds’ species composition of the maple consortiums in winter. It is more diverse than in the fall. Mistletoe infects maple quite often and its fruits also attract birds to the maple consort in winter. As a result, the birds DTB index on old generative maples is higher than on oak this time of year. The birds’ species composition in g2–g3 maple consortiums is represented by 14 species in winter. This figure is 2.5 times more than in autumn. The virgin maple consortium has a high birds DTB index in spring. The main reasons are – this tree vegetation early start and the dense thickets formation of this tree young growth. As a result, the virgin maple has a diverse trophic base for birds in the spring. This consortium is comparable with the consortium of g1maple in the birds’ species composition and exceeds it in the DTB index. The time budget of birds’ trophic interactions is 75% of the total DTB in the maple consort at the age of virg. The time budget of the bird topical interactions is 80% of the total DTB in the g1 maple consortium. The birds almost do not hunt on this age maples, but show a variety of behavioral activity. The birds’ community in the g2–g3 age maple consort is very diverse in spring and yield in to that only in old generative oak. The time budget of the birds’ topical interactions is 75% of the total DTB in the g2–g3 maple consortium. Thus, birds use g2–g3 maple in spring mainly for singing, resting, cleaning feathers, mating games, etc., rather than feeding.