Adaptations of the hooded crow (Corvus cornix Linnaeus, 1758) to urban environment

The crow birds are an inalienable component of anthropogenic ecosystems and the most successful species is the hooded crow. The success of a species depends on the conformity of a speed of adaptation process to the change rate in the environment. Organisms, adapting to the new environmental parameters in the city, demonstrate adaptive mechanisms, and can be a model for studying the evolutionary process. The process of urbanization of the hooded crow continues at present in many parts of its range, but the causes and mechanisms of these processes are not fully understood. The tasks of our research included finding out the directions and rates of the hooded crow adaptations to the changing urban environment. The research was conducted in 1997-2018. In Cherepovets, the hooded crow began to adapt to the urban environment in the late 1950s. The fastest rate of adaptations of the species was observed in the last decade. The main adaptive processes of the hooded crow in the urban system were the following: 1) territorial changes - occur at different rates, following changes in the urban development of residential buildings and in the age composition of trees, as well as changes in the culture of household waste collection service; 2) changes in the habitats of the hooded crow - are the increase in the tree species used for nesting and changes in the height of the nests, and occur during the last 15 years; 3) changes in seasonal life - in Cherepovets, hooded crows begin breeding 2 weeks earlier than in the vicinity; 4) changes in trophic links - increasing the proportion of anthropogenic feed in the diet of hooded crows as Cherepovets develops; 5) ethological changes - hooded crows became less careful at the end of the 1990s and have learned the skills of extracting food from different packages, cleaning contaminated food and dry food maceration.

To Species Diversity of Nematode Fauna of Corvidae Vigors Family, 1825 at Volga River Delta

The purpose of the research is to systematize the long-term data on study of nematode fauna of Corvidae family birds of Volga river delta. Materials and methods. Data of helminthological researches carried out during the period from 1936 to 2017 in different landscape zones of Volga river delta are included into the project. The study of the species composition of the nematode fauna was carried out based on analysis of own and literature data received during helminthological autopsy of the Corvidae family birds belonging to 3 species: hooded crow (Corvus cornix Linnaeus, 1758), rook (Corvus frugilegus Linnaeus, 1758), magpie (Picapica Linnaeus, 1758). Traditional methods were used during collection and handling of helminthological material (Skryabin, 1928; Dubinina, 1955). Nematodes have been fixed by the mixture made from equal parts of 70% alcohol, lactic acid and 50% glycerol, 4% formalin solution or in Barbagallo liquid. Nematodes have been identified by famous indicators. Results and discussion. 480 specimen of Corvidae family birds, 170 specimen of which had been infested by nematode worms, were investigated in order to study helminthofauna at Volga river delta from 1936 to nowadays. Having summarized the literature data with the results from own study of Corvidae family parasitophauna we have made a taxonomical list including 17 species of nematodes. During the period from 1976 to 2017 we have been discovering 3 species of nematodes for the first time: Microtetrameres helix (Cram, 1927) - in a rook, Oxyspirura sygmoidea (Molin, 1860) - in a rook, a magpie and a hooded crow, Pseudaprocta decorata (Li, 1933) - in a magpie. 2 species of nematodes have been registered in Corvidae family as in new hosts in the studied region too. Baruscapillaria corvorum (Rudolphi, 1819) - in a hooded crow, a magpie and Diplotriaena tricuspis (Fedtschenko, 1874) - in a hooded crow.