Structure of the community of nesting birds in a ravine oak wood in the valley of the Oskol river

Abstract

This investigation was carried out in a forest on the southern borders of the Central-Russian Upland, on the Prioskolsky plateau, in the Srednedonskoy subprovince of the Pontic steppe province. The aim of this work is to identify the peculiarities of structure and ways of formation of the breeding population of ravine oak forests on the border of two geographic zones. The objectives of the work were to describe quantitative and qualitative characteristics of the population of the nesting birds of ravine oak forests, as well as provide an analysis of the faunogenesic structure of the nesting bird population. To obtain data on the species composition and density of nesting birds we used the line transect method by D. Hayne – Y. Ravkin. The surveys were carried out in 2011–2015 three times per season (April to June). The indicators of the breeding density of each bird species and the totals for each year were calculated. The Polydominant Simpson index was used to characterize species diversity. To evaluate the uniformity we used the calibrated version of G ‘Alatalo index F’. The calculations were performed using the program PAST. In total we observed 34 species of birds over the 5 years of research. The dynamics of the total density of breeding birds in the period researched (2011–2015) showed a maximum in 2013 (1,711 pairs/km2); the average index for the 5 years was 1,288 ± 133 pairs/km2, which is similar to the characteristics of the populations of birds forests of the steppe zone (Donetsk Ridge, Azov Upland). The dominant and subdominant species comprised 32.2–54.7% of the population, indicating a balanced community, in spite of the insular nature of the forest. The absolute dominant in all years was the Chaffinch (an average of 21.2% of the population); subdominant species were the Robin (11.2%), Great Tit (10.5%) and the Collared Flycatcher (10.3%). Over a third of the total number of birds are the hollow-nesting birds (37.1%); species nesting in the crown were 32.3% and ground-nesting species 25.3%. The geographical and genesis structure of the communities of nesting birds are characterized by predominance of species from Nemoral and Ancient-Nemoral faunal assemblage (in some years up to 90.9% of the population). The species from the forest-steppe faunistic complex of the European type of fauna account for 3.6% to 9.48% of the population of nesting birds, and most of these have the status of third-degree (rare species). The composition of the group of third-degree species is highly diverse: in addition to the elements of Nemoral, Ancient-Nemoral and forest-steppe complexes, it includes species from the tropical and boreal groups. Among third-degree species there is a tendency to decrease in some species from the Nemoral faunal complex with a simultaneous increase in the forest-steppe faunistic component and increase in the homogeneity of the geography-genesis structure as a whole. The significant share of the population from the Nemoral and Ancient-Nemoral species complex, which formed in deciduous forests, is evidence of the origin of the researched ravine oak wood as a remnant of the once vast oak-forest areas.

A Soundscape Assessment of the Oak Forests in the National Park “Homilshanski Lisy” (Northeastern Ukraine)

“…In some cases, the average number of species identified using AudioMoths exceeded the average number of species identified using more expensive recorders, as well as the results of point counts (Toenies, Rich, 2021). Our results also show that the data obtained with Audi-oMoth devices is generally consistent with both data obtained with more expensive devices (Atemasov, Atemasova, 2019) and the results of point counts (Atemasov et al, 2010(Atemasov et al, , 2011.…”

“…In 2007-2009, point counts were carried out on this territory to obtain data on the species composition and population density of nesting birds. On an area of about 400 ha, 108 points were laid, and a threefold count was carried out during each nesting season (Atemasov et al, 2010(Atemasov et al, , 2011. During these studies, there was no separation of credentials by age categories of the forest.…”

“…During the entire period of research, 47 species of birds were recorded, of which 42 species were nesting. The total population density ranged from 3295 to 3870 pairs/km 2 (Atemasov et al, 2010(Atemasov et al, , 2011.…”