Determining the diet composition of the African manatee: spatial and temporal variation within the downstream of Sanaga River watershed, Cameroon.
Downstream of the Sanaga River Watershed (DSRW) is considered the area with the highest occurrence of the African manatees in Cameroon; within the watershed, Lake Ossa is thought to be a refuge for the manatees during the dry (low water) season. Although knowledge about diet composition of the species is unkown for this area, this study will provide information on the feeding ecology and habitat use of manatees necessary for determining their conservation status. The African manatees in the DSRW are not well known regarding their needs for plant diet composition. The goal of this study is to identify and document key plant species consumed by African manatees in the DSRW and assess the difference in diet composition by location/habitat, season/water level, size class, and accessible plant species diversity and abundance. To describe and characterize diet composition, microbiological analysis will be performed on 300 free-floating manatee fecal samples, and ingesta samples collected from manatee carcasses, during two separate seasons (dry and wet) at five different locations representing four habitat types.
For the comparison, measures of factorial variables will be recorded, including average water depth at each site and each season, the general area of fecal sample collection (assuming that high counts represent group size of the species), species richness, the Shannon index, and relative abundance of available plant species. A multifactorial ANOVA will be used to staistically compare diet composition among the different factor levels of interest. The results of this study will provide the first comprehensive list of manatee food plant species for African manatees in Cameroon. Also, the understanding of the spatiotemporal variation of the manatee diet will help to hypothesize on the necessity of migration and determine site-fidelity patterns dependent upon vegetation, especially during the low water season.