RESULTS 



The density of Derby Eland was found as 0.85 animals/ km^ in Benoué National Park. Below is the GIS 

 map of BNP showing the distribution of Derby Eland as Figure 1 ; while Table 1 , shows the encounter 

 rate of Derby Eland and other big games observed directly in Benoué National Park. IKA is a bio- 

 indicator index to characterize the abundance of animal population. 



Table 1: Encounter rate of Derby Eland and other big games in Benoue National Park. 

 Species Number of animals Distance of IKA 



The total animal biomass, percentage contribution and biomass per hectare for Derby Eland and other 

 big game in Benoué National Park was calculated (see Table 2). 



Table 2: Estimated biomass, of some big game in Benoue National Park (1,800 ha) 



AW = weight of male plus weight of female divided by 2 

 O = Number of observed animals 

 AW * O = AW multiplied by O 



The total biomass, percentage contribution and biomass per hectare for Derby Eland is 22860, 6.65% 

 and 12.7 in Benoué National Park. Calculated values for the biomass can be compared with standard 

 values to determine the threshold at which wildlife species are at maximum sustainable yield (MSY) or 

 at minimum sustainable yield in a National Park. Maximum biomass of wildlife at maximum 

 sustainable yield (MSY) is 0.22 or about 35% of the biomass at maximum sustainable yield (BMSY) 

 level. Minimum Biomass threshold is Vi BMSY (Mid-Atlantic Fishery Management Council, last date 

 ofaccess 20/ 12/2005). 



Nature & Faune Vol. 23, Issue 1 



29n 



