Assessment of bird diversity and abundance in Mai-Nigus artificial reservoir and surrounding semi-forest in Tigray Region, Northern Ethiopia

Artificial reservoirs are alternative habitats for bird diversity, and knowledge of the diversity and abundance of bird species contribute to the management of the ecosystem. This study was conducted to investigate the species diversity and abundance of birds in Mai-Nigus reservoir and its surrounding semi-forest from July 2022 to March 2023. Point count method with a total of fifteen count stations at an interval of 50 m radius was used to study the diversity and abundance of bird species in the semi-forest habitat while total count employed on the reservoir. A total of 123 bird species comprising endemic and globally threatened species were identified. Order Passeriformes had the highest number of species followed by Charadriiformes and Pelecaniformes. Family Scolopacidae was the most abundant followed by Ardeidae, Ploceidae and Anatidae. Bird species richness and abundance were not significantly varied across seasons and habitats (P > 0.05). The highest species diversity (H´=3.96) were recorded in the Semi-forest during the wet season, whereas the least was recorded from reservoir during the dry season (H´=2.66). The highest and lowest species evenness of birds was recorded in Semi-forest (E = 0.725) and reservoir (E = 0.448) during the dry season, respectively. Most birds that inhabited the area had frequent relative abundance followed by uncommon and common species. Mai-Nigus reservoir and surrounding habitat host high bird diversity and this requires critical conservation concerns for the long-term survival of birds.