Distribution of sunbird species within and around the Amurum Forest Reserve, Nigeria

Abstract

Monitoring the distribution of bird species across a landscape provides information on habitat occupancy and utilization. This study determined the distribution of the five sunbird species (variable sunbird, scarlet-chested sunbird, green-headed sunbird, copper sunbird and pygmy sunbird) known to exist within the Amurum Forest Reserve. Distribution was determined both within and outside the Amurum Forest Reserve and across the habitat types in the area (gallery forest, savannah scrub and rocky outcrop) and anthropogenic scales (roads, houses and farmlands). The study was conducted between September to October 2014 using presence and absence data. A total of 60-sample points were selected using stratified random sampling. The presence or absence of the candidate bird species was determined across all points after two visits. The study revealed the variable sunbird, Cinnyris venustus as the most widely distributed of the five sunbird species this sunbird species also occurred across all habitat types equally as compared to the scarlet-chested sunbird, Chalcomitra senegalensis which was more skewed in distribution towards the rocky outcrop areas of the reserve. The sunbirds also appeared to utilise areas of anthropogenic disturbance when outside the reserve perhaps due to the presence of several green areas outside of the reserve. The uneven distribution of the birds across the landscape may as a result of niche partitioning to avoid competition. Also, lack of presence of the other sunbird species throughout the period of study was linked to their migratory behavior as reported in some literatures. The study re-emphasizes the importance of the Amurum Forest Reserve as a good refuge for birds in the area.