Effects of Land-use on Birds Diversity in and around Lake Zeway, Ethiopia

Abstract

Anthropogenic factors can have major impacts on ecosystem functioning and stability, which are often reflected in changes to the biodiversity that includes wildlife. Land-use is a dynamic process that changes in space and time depending on prevailing socio-economic and biophysical conditions. This study aims at investigating anthropogenic effects of land-use on bird species diversity and abundance in and around Lake Zeway. Systematic random sampling techniques at an interval of 4km were used to select sampling blocks. A transect line of 1.65km and a sighting distance of 300m on both sides of a given transect, depending on species and habitat types, were laid along each block to count birds. Satellite images and Environment for Visualizing Image (ENVI) were used to analyze and detect land-use and cover changes in the surrounding areas of the Lake. The study revealed that land-use and cover related to bird community have changed during the analysis period in the area. Relatively low bird species diversity was recorded in blocks with less vegetation cover as compared to blocks with relatively intact vegetation cover. Bird species diversity showed significance difference among different species (F = 39.326, df =11, P < 0.05). In terms of feeding guild, carnivorous had the highest species richness and diversity, while Piscivorous feeding guild had the least. Diversity of birds community with changes in vegetation cover showed significant difference (F = 6.613, df =21, P < 0.05). Moreover, abundance of bird species was relatively higher in dense vegetation cover sites and areas with permanent ponds. From the results, it can be concluded that variations in the diversity and abundance of bird species variably affected by land-use and land cover types. The major reason for such change is conversion of land to irrigated agricultures in the surrounding areas of the lake. Thus, urgent conservation measures that could reduce the impact of land-use/cover changes are needed to conserve the bird species at the lake.