Characteristics of Great Bustard (Otis tarda) (Otididae, Aves) Habitats in the Trans-Volga Region according to Food Availability during the Chick Rearing Period

• Published in: Biology bulletin of the Russian Academy of Sciences Vol. 49; no. 10; pp. 1898 - 1908
• Main Authors: Oparina, O. S., Oparin, M. L., Kudryavtsev, A. Yu, Oparina, A. M.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2022; Springer Nature B.V
• Subjects: Agricultural production; Arthropoda; Arthropods; Biochemistry; Biomedical and Life Sciences; Cell Biology; Crop rotation; Crops; Ecology; Food availability; Food supply; Habitats; Juveniles; Life Sciences; Otis tarda; Plant communities; Wheat; Zoology; biomass; habitats; plant communities; arthropods; abundance; Trans-Volga region; bustard; food base
• DOI: 10.1134/S1062359022100272
• ISSN: 1062-3590

The results of our studies of potential nesting sites for bustards in the Saratov Trans-Volga region are presented. The characteristics of plant communities, as well as the quantitative and qualitative composition of arthropods in these areas, are given. Specific materials obtained in the years 2017–2021 at six plots are given, namely, crops of winter wheat, millet, and sunflower; fallows of various ages: and young (2nd stage) and old, virgin lands. The results obtained are compared with the data of previous years. The results on the state of the forage base of bustards allow us to conclude that loss of nesting habitats by birds of this species has actually occurred. Those areas where, despite the decrease in the abundance of insects, there are still enough of them to feed the chicks, are not used by bustards as nesting habitats. These are fallows of various ages and virgin lands. The lack of a sufficient number of arthropods necessary for feeding chicks in those sites where bustards prefer to nest, namely, cereal crops, leads to catastrophic consequences for reproduction, and, consequently, for the survival of the species. The numbers of large orthoptera and beetles in winter crops, reflecting biomass indices, have decreased by ten times compared to 2000, during the period of extensive agriculture. The intensification of agricultural production, the use of pesticides on various crops, and the change in the structure of crop rotation are the main causes for the insufficient food supply during the period of rearing chicks. The results obtained give grounds to believe that the number of bustards will continue to decline due to their inability to raise their offspring as a result of a shortage in food supply.