Effectiveness and cost efficiency of monitoring mountain nyala in Bale Mountains National Park, Ethiopia

Due to the financial limitations faced by many protected areas today, identifying costefficient monitoring protocols has become important in ensuring the long-term sustainability of conservation.The selection of monitoring protocols is usually driven by a range of factors, such as widespread practice or accuracy, but the cost efficiency of protocols is rarely considered.The mountain nyala Tragelaphus buxtoni, classified by the IUCN as Endangered, is endemic to the Ethiopian highlands.This species has high economic potential for local communities through tourism and trophy hunting, but the expansion of human settlement is causing habitat degradation and fragmentation.A significant proportion of the global mountain nyala population occurs in Bale Mountains National Park (BMNP); thus the development of a long-term monitoring protocol was identified as a priority.Like many protected areas, the BMNP is operating well below its financial needs; hence developing a robust, cost-effective method that can detect changes in population size is important.We compared the effectiveness and cost efficiency of distance sampling and total counts.Results showed that while the population estimates were relatively similar, total counts under estimated population size but were more precise, had a greater power to detect changes in population size and required only 12% of the resources needed compared to distance sampling.We suggest that investing in initial comparisons of the effectiveness and costs of different methods can result in significant cost savings, without jeopardizing the effectiveness of a survey.