Seasonal changes in composition and numbers of bird species on the territory of the Yerevan Botanical Garden

This study was conducted in the Yerevan Botanical Garden from 2022 to 2023. The transect method, widely recognized for its effectiveness in studying bird populations across diverse habitats, was employed to monitor birds in the garden. To assess bird diversity, we utilized two widely accepted diversity indices: the Shannon-Wiener index and the Simpson diversity index. Over the course of the research, 54 bird species were recorded in the Botanical Garden. These included 16 sedentary species, 13 nesting species, 9 wintering species, and 9 migratory species. Additionally, 7 species were observed sporadically as single (random) occurrences. Notably, we documented an unexpected observation of Eurasian Siskin (Spinus spinus) in June, a species traditionally considered a wintering bird according to the available literature. Seasonal variations in species composition and abundance were evident. The highest species richness was recorded in open habitats during spring, while the lowest was observed in forest habitats during autumn. Similarly, the number of individual birds peaked in open habitats during summer and declined in winter. The presence of five threatened species, including four listed in the Red Book of the Republic of Armenia and two on the IUCN Red List, underscores the Yerevan Botanical Garden’s significance as a sanctuary for bird conservation.