The article gives a space-structural characteristic of rook (Corvus frugilegus) nesting places in the territory of Botievo wind farm (Zaporizhzhia region). The distribution of the rook colonies around the territory, the structure of the colonies, the dependence of the location of the nests on the height, diameter, condition and species composition of tree and shrub plantings are analyzed and studied. The types and methods of the localization of nests in the trees and their quantitative characteristics are highlighted. The consortium relations of the rook and the risks associated with living near existing wind turbines are described.In 2015 some eight colonies were found: 2 medium (51-100 nests) and 6 large (101-500 nests) ones. All the colonies were located in the forest belts, mainly represented by locust trees Gleditsia triacanthos (7 colonies) and in the mixed forest consisting of the mulberry Morus sp., maple Acer, black locust Robinia pseudoacacia, and locust trees (1 colony). The area occupied by colonies had a four-fold difference between 977-3994 m 2 , while the number of the rook nests fluctuated in a seven-fold range -52-343 nests.Analysis of different indicators describing the structure of the rook colonies revealed certain dependence between the breeding area and the number of the occupied trees (r = 0.97); the breeding area and the number of nests (r = 0.60); the number of nests in the colony and the closeness of the trees in the forest belts (r = 0.91); the number of nests and the number of the occupied trees (r = 0.74), the height of the tree and the nest on it (r = 0.64). The characteristic of the location of nests in different rows of the forest belt revealed the shift of the density of the occupation of trees in large colonies to one of the outer rows, where there were 26.0-27.5 percent of all the nests.Typology and localization of rook nests in the trees has 11 options of the location. The type of the location of nests near the trunk of the tree dominated (57.4 percent of trees and 64.5 percent of all nests). It is shown that rooks demonstrate the plasticity of the nesting behaviour to the changing environmental conditions. Keywords: Rook (Corvus frugilegus), Zaporizhia region, wind farm, nesting area, colony structure, spatial distribution, colony.Colonial nesting is a testing ground for the development of many biological problems: the theory of evolution and understanding of the factors of microevolution,
The article contains the results of observations on the formation, existence and the dissociation of the collective winter roost of corvids (crow species) in 2014–2015 in Melitopol (Zaporozhye region). A detailed study of the concentration and the dynamics of its functioning during the winter period was carried out. By the method of absolute counting of birds, the estimation of the gathering process on the roost in the night and dispersal from roost in the morning was carried out twice a week (a total of 47 days of observation in the morning and evening). We selected the following essential parameters: time of the beginning and ending of the process of dispersal from the roost in the morning and gathering at the roost in the evening; time – study of birds’ flight activity in these intervals; the number and species composition of birds; directions of flights with their mapping; weather conditions. Within the city of Melitopol during the winter period of 2014–2015, corvids (Rook, Western Jackdaw, Eurasian Magpie and Common Raven) form one central roost. The total number of birds at the roost was typically 18 thousand individuals. The collective roost exists from the beginning of October till the end of March. The analysis of dynamics of the birds’ number during the existence of the collective showed a wide amplitude of fluctuation in the range of 1,000–5,000 individuals during autumn (10 times) and spring (5 times) migration. By the end of November migration ends, the number of birds has stabilized, and the location of the night roost becomes permanent. In winter the gathering is more stable and fluctuations in number lie within the limits of 500 individuals (8 times). The number of birds that roost collectively decreased from mid – March. In this article considerable attention is paid to processes of the birds’ dispersal from the roost site and gathering at the roost at night. The observations showed a high degree of dependence on day length and different intensity of these types of daily activity. During the analysis of the process of morning dispersal of birds from the collective roost, seasonal differences in the time of dispersal were found. In the winter months this period was significantly shorter than in the autumn and spring. The duration of dispersal of birds from the roost (28.4 ± 9 min; lim – 15–45 min) was reliably less than that of gathering at the roost (87.9 ± 14.8 min; lim – 30–115 min); the difference of averages is significant for the highest probability threshold of р ≥ 0.001 for the entire observation period. As a result of research on dispersal and gathering of birds at the roost site, the basic strategies of the birds’ behaviour were revealled. For morning dispersal of birds from the territory of the roost the strategy of “gathering with a pause” (16 registrations; 35.6%) is dominant. The strategy of “the damped wave” is sub dominant (14; 31.1%). The lowest percentage was taken up by the strategy of “three peaks” (1; 2.2%). For the evening gathering of birds at the roost, the strategy of “two peaks” is dominant. The lowest percentage was taken up by the strategy of “gathering with a pause” (2; 4.5%). The overall species diversity within a gathering and on the routes of birds’ flights reached 24 species. The undisputed dominant in numbers was the Rook, and the subdominan was the Jackdaw. Thus, corvids form the basis of the ornithological complex of the forest – park zone of Melitopol in the autumn and spring period.
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