Diversity and Relative Abundance of Wet Land Birds in the Laga Dadhi Artificial Reservoir, Oromia National Regional State, Ethiopia

Abstract

Wetland ecosystems are among the most productive and ecologically significant habitats, providing vital resources for avian species. This study aimed to assess the species, diversity, and relative abundance of avian species in Laga Dadhi Artificial Reservoir located in Oromia, regional stat of Ethiopia. It was conducted from July 2024 to February 2025 during wet (July August 2024) and dry (January–February 2025) seasons. Five habitats (wetland, farmland, woodland, grassland, and settlement) were identified for counting birds using line transect walk and point count methods. A combination of direct field observation and semi-structured interviews with local residents and farmers was employed to collect data on threats to avifauna. Data were analyzed using Shannon-Weaver and Simpson’s diversity Indices and Simpson’s similarity index. T-test and ANOVA were applied for analysis of the effect of season and habitats on abundance of species. A total of 74 bird species belonging to 12 orders and 31 families were identified, including two critically endangered species (Hooded Vulture and White-backed Vulture) and endemics such as the Blue-winged Goose and Rouget’s Rail. A total of 3,460 individuals were recorded across habitats and seasons. Statistical analysis (ANOVA) revealed significant differences in bird abundance across habitats during both the wet (F = 3.182, p = 0.014) and dry (F = 3.545, p = 0.007) seasons, although no significant variation was observed in overall abundance between seasons (p = 0.641) or species richness across habitats (p = 0.145). Farmlands exhibited the highest Shannon diversity index while woodlands recorded the lowest, possibly due to degradation. Threat assessments indicated that agricultural encroachment, deforestation, overgrazing, and pollution were the most pressing challenges facing avifaunal conservation in the area. The findings highlight the reservoir's ecological importance as a habitat for both resident and migratory bird species and its vulnerability to human-induced disturbances. The study recommends habitat restoration, the establishment of buffer zones, community-based conservation programs, seasonal bird monitoring, and policy integration to ensure the long-term protection of bird diversity and wetland ecosystem services in the region.