Distribution and numbers of Delichon urbicum in the Nizhny Novgorod Oblast

The paper aimed to evaluate the current state of the breeding population of the house martin Delichon urbicum in the Nizhny Novgorod Oblast based on the analysis of the results of our field surveys and data collected by citizen science. Based on repeated counts of nests in 10 colonies, we discovered the number of house martins decreased by an average of 7.16% per year from 2012 to 2024. Based on the average annual population decline, the probable number of nests in 49 colonies from 786 to 916 nests is calculated in 2024. The calculated regional number of house martins ranges from 2,116 to 2,488 pairs. The prospect of further research is the organization of a regional census of the house martins, the development of the database of colonies and further monitoring of the species conditions in the Oblast, and the implementation of European experience in artificial nest erecting.