The Status and Distribution of the Clawless Otter ( Aonyx capensis ) in Vwaza Marsh Wildlife Reserve and Nyika National Park, Northern Malawi

摘要

William O. Mgoola and Hetherwick G.Msiska The clawless otter ( Aonyx capensis ) occurs in Nyika National Park and Vwaza Marsh Wildlife, Northern Malawi. A number of rivers, streams and other wetlands areas were searched for otter signs (spraints, tracks, dens, runs, food remains). The species status in Nyika could be rated as common and sparse in Vwaza. The clawless otter commonly occurs in Nyika; all the wetland areas surveyed indicated positive otter signs. A total of 790 signs were recorded in Nyika National Park, these signs were registered most frequently in riverine habitats in northern hills, followed by montane riverine habitats on plateaus and southern hills wetlands. There is no significant difference in density of otter in Nyika Wetlands (F=2.636 df= 2 and 6; P ?0 .001). This area has high potential for the survival of the clawless otter. There is abundant otter prey (fish, crabs), adequate vegetation cover, water, and reduced human activity. Aonyx capensis in the Vwaza Marsh Wildlife Reserve were recorded only in the marsh (247 signs) and very rare in downstream areas. Luwewe and South Rukuru rivers remained negative with no evidence of otter occurrence. The habitat in the marsh is ideal for the survival and existence of otters, adequate vegetation cover, water and prey. The main threats observed in Nyika National Park include illegal bushfires, fish poaching especially in northern hills wetlands, and soil erosion. The major factors of stress in Vwaza Marsh Wildlife Reserve are streambank cultivation, riparian vegetation destruction, siltation, illegal bushfires and competition for fish and crabs between humans and otters. Broad-based conservation measures are proposed for long term survival and existence of clawless otter and its habitats.