Diversity, distribution and relative abundance of avifauna at Ansas Dam and surrounding farmland site Debre Berhan Town, Ethiopia

Abstract

The diversity, distribution, and relative abundance of avifauna were studied at and Around Ansas Dam, Debre Berhan Town, Ethiopia, from early September 2018 to early February 2019, covering both wet and dry seasons. Line transect technique was employed to study the diversity, abundance and distribution of birds species in the farmland site while total count employed on the dam. Data were collected in both wet and dry seasons from 6:30 to10:00 early morning and 15:30 to 18.00 late afternoon, when birds are more active. The data were analyzed with Shannon-Weiner Index, Simpson Index, Evenness Index, and relative abundance. A total of 45 bird species (35 in the dam and 22 in the farmland) belonging to nine orders and 21 families were recorded during the study period. Order Passeriformes (37.8%) followed by order Charadriformes (24.4%) were represented highest number. From all identified species at Ansas Dam and surrounding farmland, Abyssinian longclaw, Black-headed siskins, White-tailed swallow, Blue-winged goose, and Spot-breasted lapwing were endemic birds to Ethiopia. The highest Shannon diversity (H′ = 2.1) was recorded in dam during the dry season while the lowest (H′ = 1.78) was recorded during wet season in farmland. However, the Simpson diversity Index of avian species indicated relatively higher avian species diversity during the dry season in dam (D = 0.80) than farmland (D = 0.71) habitat. Evenness was highest in the dam (E = 0.65) and lowest in the farmland (E = 0.58) habitat. More avian species similarity (SI = 0.42) at farmland and dam habitat during the wet season but least similarity (SI = 0.2) was observed during the dry season. Most birds had scored rare in the ordinal scale while few species with abundant and uncommon ranks in both habitats and seasons. Conservation of the different charismatic bird species should be taken as an important component of wildlife management plan in the area.