Effects of urban land-use types on avifauna assemblage in a rapidly developing urban settlement in Ghana

Given that rates of urbanization are rising globally, the need to maintain and enhance urban biodiversity has become important. This study examines the relative influence of different land-use types as well as environmental resources (trees, flowering trees, fruiting trees, shrubs, telecommunication mast, pylons, electric poles, buildings) on bird diversity indicators in a rapidly developing urban settlement in Ghana. Remote sensing was used to estimate the extent of conversion of natural habitats into urban settlements. Using point count surveys, bird species were recorded and compared in randomly selected plots of four land-use types of farmlands, remnant forest, residential and commercial areas. We further evaluated the relative influence of habitat resources on bird diversity indicators. We found a significant expansion of built-up areas into natural habitats in the study area. Also, there has been a significant increase in sparse vegetation coupled with a drop in the area covered by dense vegetation over the last three decades. Avifauna diversity indicators differ significantly across the four land-use types with urban farmlands being the most species diverse, followed by urban remnant forests, then residential and finally commercial areas. Our findings suggest that avian species diversity indicators decreased significantly with increasing land-use intensity and revealed that the study area still possesses significant conservation potentials for urban birds and by extension biological diversity as long as vegetation fragments are maintained within a sustained urban expansion framework. We propose increasing the quantity and complexity of the vegetation cover in residential areas by supporting citizens to establish private yards to increase the city's green network.