Night and day: evaluating transect methodologies to monitor duikers in the Dzanga-Sangha Protected Areas, Central African Republic.

Across the Congo Basin, human hunting pressure poses the biggest threat to small- and medium-bodied forest ungulates (genus Philantomba and Cephalophus, commonly known as duikers). The exploitation of these species has cascading effects on larger ecosystem processes, as well as on human subsistence practices. This study compares encounter rates and estimated population densities of duiker species, specifically Philantomba monticola (blue duiker) in the Dzanga-Sangha Protected Areas ( APDS), Central African Republic ( CAR). Data were collected using direct observations of individual animals during diurnal (135 km) and nocturnal (150 km) transects in the APDS, with abundance estimates produced using DISTANCE software. Transect data demonstrate that within hunted forests similar to APDS, nocturnal rather than diurnal transects yield more individual observations of ungulates. Despite hunting pressure in the region, estimates presented for APDS suggest some of the highest density estimates reported for blue duikers in western and central Africa (58.6 blue duikers per km2). This study directly contributes current regional data on the status of duiker populations at APDS and in the larger Sangha Trinational Landscape ( TNS, UNESCO). More broadly, we highlight the potential importance of nocturnal transect data to the development of adaptive management regimes in hunted forests. [ABSTRACT FROM AUTHOR]