Species Diversity, Distribution, Relative Abundance and Habitat Association of the Avian Fauna of Modified Habitat of Bahir Dar and Debre Mariam Island, Lake Tana, Ethiopia

摘要

The study was carried out along the southern shore of Bahir Dar gulf (Lake Tana) and Debre Mariam Island from August 2006 to March 2007, covering both wet and dry seasons. Sampling sites were stratified based on the vegetation type and area cover. Point count technique was employed. A total of 154 bird species consisting of three endemic, two globally threatened, and 33 Palaearctic migrants were identified. The species diversity index and evenness of habitats during the entire season of the study periods revealed that Debre Mariam Island had the highest species diversity and evenness, 0.94 and 0.88, respectively. The relative abundance score of each species was variable. The number of species recorded in the modified habitat of Bahir Dar during the wet and dry seasons was 74 and 107; and in Debre Mariam Island 28 and 33, respectively. The mean number of species in the wetland vegetation stratum was (7.50), followed by papyrus bed (5.67), garden (5.57), trees and woodlands (5.00), and fruit trees (4.00). Chi-square test for the wet season showed that the association of birds with the vegetation stratum was not statistically significant (P > 0.05, chi-square =5.846, df =8, n= 26). But, during the dry season, it was significant (p < 0.01, chi-square = 33, df = 11, n = 51). Deforestation, cultivation and pollution were the main threats for the survival of bird fauna in the area.