We conducted a line-transect survey via direct observation to estimate the densities of forest duikers in Moukalaba-Doudou National Park, Gabon. Five 2-km line transects were established in different vegetation types, and each transect was walked at 1.0 km/h. We also conducted a ‘quick survey' by walking at c. 2.5 km/h along all transects. A detection function was estimated separately for each species by pooling all the data from the five transects. For Cephalophus silvicultor, all sighting records of the two surveys were used because there was no significant difference in the encounter rates. In total, Philantomba monticola, red duikers (Cephalophus spp.), and C. silvicultor were observed 100, 80, 33 times, respectively. Their individual densities were estimated at 16.43/km2 (95% CI: 11.4–23.6), 7.1/km2 (5.5–9.2), and 1.63 km2 (1.0–2.8), respectively. The encounter rate for P. monticola and C. silvicultor did not vary significantly between the transects, while that of red duikers was higher in the primary forest than in the young secondary or gallery forest. The duiker densities in our study area are among the highest in the African rainforest. Our results indicate that quick surveys may be an effective approach to estimate the densities of rare species.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.