Ecological and evolutionary aspects of the nesting life of black-headed gulls Larus ridibundus) as a colonial breeding species

This article analyzes the ecological and evolutionary aspects of the nesting life of the black-headed gull (Larus ridibundus), which leads a synanthropic lifestyle and forms colonies during the breeding season. The number of individuals belonging to this species began to increase rapidly at the end of the 19th century, which is a manifestation of one of the criteria for biological progress. This direction of evolution is associated with an increase in the level of adaptability of descendants in comparison with their ancestors. The progressive nature of the development of the species affects the stages of the annual life cycle, which includes the pre-breeding and nesting periods. During the pre-nesting period, birds arrive in the nesting area and select a site for the colonial settlement. Arrival dates are determined by temperature, the state of aquatic ecosystems and the physiological characteristics of birds. The nesting period includes the construction of a nest in a certain part of the territory on which the colony is being built. The process of colony formation occurs in stages: single nests, microcolonies, biological center. After the formation of the biological center, nests are built on the periphery. The formation of this part of the colony according to the same stages as the biological center. The biological center deals with the birds that arrive first on the territory of the colony. This area within the colony differs from the periphery in early terms of formation and high density of nests. In the formed colony, the biological center and periphery are distinguished. The colony as a supraorganismal structure is built under the influence of environmental factors that provide a sufficient level of adaptability of this group of individuals to the environment. The obtained materials will make it possible to study monospecific and polyspecific colonies as groups of individuals that exist on the basis of the manifestation of biocoenotic relationships.