Species diversity and abundance of wild birds in Dagona-Waterfowl Sanctuary Borno State, Nigeria

Abstract

The study of bird species diversity and richness in Dagona-Waterfowl sanctuary was carried out in early wet and late dry seasons. This was to provide some information on the wild birds of the sanctuary. Dagona sanctuary is located within the Bade-Nguru wetland sector; it is one of the important bird areas strategized for the conservation of avifauna species in Sub-Sahara region, Nigeria. Line transect method was used to carry out birds’ survey at three different lake sites, namely: Gatsu (Site:1), Mariam (Site: 2) and Oxbow (Site: 3). The data were analyzed with the Kolmogorov- Smirnov test to determine the distribution level of the birds. The birds’ diversity was assessed using Shannon-Weiner diversity index. The results showed that bird species diversity was not equally distributed in the sites Site 2 had the highest diversity with an index of 2.74 compared to Site 1 with 1.84 and Site 3 with 1.62. Likewise, bird species diversity in the area was normally distributed birds’ abundance were significantly different (P<0.05) among the three sites. Site 1 had the highest number of bird (16.36) compared to Site 2 (14.32) and site 3 (11.51). It was observed that there was a significant relationship between vegetation density and bird species diversity; because as tree density increases, diversity of bird species decreases. Therefore, there is a significant relationship between vegetation density and bird species diversity. Total number of 135 bird species in 40 families was recorded during the survey. Seventy-four percent were found in site1, sixty-three percent in Site 2 and seventy-one percent in site 3. The birds that were observed during this study were made up of resident (Ardeidae family), migratory (Accipitridae family) and palearctic species (yellow wagtail, warblers, northern shoveler and sandpipers). It can be concluded that wild birds are good indicators of the ecosystem, revealing the state of the wetland. Some sites were more disturbed, as observed in site: 1 and site: 3. It was however recommended that regular monitoring of the sites should be carried out so as to control changes in the state of wetland ecosystem.

Key words: Wetland, birds, diversity, richness, vegetation.