Assessment of the Large Mammals of Arakhuan Range, Okomu National Park, Nigeria

Abstract

An assessment of the large mammals of Arakhuan Range, Okomu National Park, Edo State, Nigeria, was carried out using land transect methods. A total of 12 large mammalian species were observed (eight directly and four by their signs). These are made up of four primate species; Red-capped mangabey (Cercocebus torquatus), Mona monkey (Cercopithecus mona), White-throated monkey (C. erythrogaster pocoki), and Putty-nosed monkey (C. nictitans ludio), three species of antelope: Maxwell duiker (Cephalophus maxwelli), Yellow-backed duiker (Cephalophus silvicultor), and Red-flanked duiker (Cephalophus rufilatus), and a species of mangoose (Herpestes sp). Those observed through their activities were forest elephants (Loxodonta africana cylotis), forest buffalo (Syncerus caffer nanus), civet cat (Viverra civetta) and the red river hog (Patamochoerus porcus). Altogether, 145 sightings of animals were recorded during the study period. Mona monkeys were most commonly sighted (sighted 37 times, producing 0.22 sighting/km)^-2 and population of 1970.93±412.93 individuals. The yellow-backed duiker was very rare in the range as it was sighted three times with an estimated population of 9 ± 2 individuals. There is very strong correlation between sightings in the morning and that of evening (r = 0.94, P < 0.05). However, there were significant differences in sighting on transects (χ2 cal. = 35.18, χ2 tab. = 32.7, df = 10, P < 0.05) indicating that sightings are transect-dependent. Over 50% of all sightings were achieved in the matured forest.

Keywords: Mammals, line transect, sightings, estimated population.