Comparison of avian species diversity and abundance in seasonally flooded wetlands in eastern part of Lake Tana, Ethiopia

Abstract

The Lake Tana area owns several wetlands and is one of the best places for local and migratory birds in Ethiopia. The wetlands are subjected to anthropogenic pressure, which in turn affects wetland-dependent fauna and flora. This study aimed to assess species diversity and the abundance of birds in the flooded wetlands. The transect and point count methods were used to locate birds across five sites from December 2021 to November 2022. Bray-Curtis cluster analysis was used to show the species composition similarity of waterfowl across the study habitats, and Shannon-Wiener diversity indices (H′) were employed to quantify the diversity of avian species. A total of 35 bird species, representing 21 families and 13 orders, were identified in the study area. Globally threatened (vulnerable) species such as wattled cranes and black-crowned cranes are common in the farming landscape and the wetlands. Shesher and Sendye wetlands had the highest richness (S = 32 and 28), respectively. The highest dominance index (D = 0.16) was found in Sendye wetland. The difference in species richness among habitats might be due to resource availability and the degree of human influence. Lake Tana wetlands have deteriorated from time to time due to heavy human involvement and a recent invasion by water hyacinth (Eichhornia crassipes), affecting the overall ecological integrity of the system. Hence, sustainable wetland management interventions, legitimate environmental preservation, and administration endeavors ought to be actualized to conserve birds in their territories.