Observations on the feeding activities of the West African Manatee, Trichechus senegalensis Link, 1795 in a semi-wild environment

Abstract

The presence of the West African manatee, Trichechus senegalensis in a semi-wild holding facility in Little Stream Farm, Ibesikpo Asutan Local Government Area, presented an opportunity to study directly, aspects of their biology, which hitherto were little known. This study was conducted to identify their plant food preferences and feeding behaviour as a reflection of what may approximate their activities in the wild. The selected plants were weighed (wet weight in kg) with spring balance in batches of 3kg per plant species and offered in batches to the manatee for a specified period (initially for 24 hours, then 4 hours and 10 hours). Of the 15 plant species presented, Emilia sonchifolia, Commelina diffusa, Nymphaea sp., Panicum laxum, Eleusine indica and Rhynchosia sp. had high preference levels while the quantity of Chromolaena sp. consumption was minimal. Bambusa sp., Heliotropium indicum, Ludwigia abyssinica and Hyptis lanceolata were ignored by the animal on repeated presentations. Studies on day-time and night-time feeding showed little difference in quantities of food consumed. However, the maximum consumption of 7kg was observed at daytime feeding on day 4 of the 14 days trial. The result showed that in the event of West African manatee rescue and fostering in temporary holding facilities, these plants’ checklists may come in handy as food materials. They may also come for important considerations as plants whose natural growth and propagation should be encouraged in areas designated for West African manatee conservation.