Estimating the abundance of forest antelopes by line transect techniques: a case from the Udzungwa Mountains of Tanzania

• Published in: Tropical zoology Vol. 17; no. 2; pp. 267 - 277
• Main Authors: Rovero, F., Marshall, A. R.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.12.2004
• Subjects: census walks; density estimates; duikers; forest antelopes; line transects; Udzungwa
• ISSN: 0394-6975; 1970-9528
• DOI: 10.1080/03946975.2004.10531208

We used line transect counts to collect data on population abundance of forest antelopes from three moist forest sites in the Udzungwa Mountains, Tanzania. The habitat quality of these forests differs in forest size, vegetation type, human impact and level of protection. The red duiker (Cephalophus natalensis harveyi Thomas 1893) was the only species regularly seen (mean of 0.16 animals seen per km walked) at one of the three sites, Mwanihana Forest, a large forest block within the Udzungwa Mountains National Park ranging in altitude from 300-2100 m. Counts of antelope tracks and dung piles were used to supplement information from areas where no direct observations were scored. This study provides the first account of the abundance of forest antelopes in the Udzungwa Mountains and confrms that methodological problems-such as poor antelope detectability due to understorey vegetation and difficulties in identifying antelope species-are inherent in estimations of forest antelope density by line transect counts. Combining counts of indirect signs with direct counts increases the information for some species and comparable data show that camera-trapping can also greatly supplement the information, especially for more elusive and/or more nocturnal species.