The Importance of the Black Lemur (Eulemur Macaco) for Seed Dispersal in Lokobe Forest, Nosy Be

Abstract

In order to classify trees in the Lokobe Forest, Nosy Be, as dispersed, possibly dispersed, or not dispersed by Black Lemurs (Eulemur macaco), two Black Lemur groups were habituated and observed during the day and night for all months of the year (total 1219 hours). When fruits were eaten, the species was identified, and the maturity of the fruit and treatment of the seeds noted. Black Lemur droppings were searched for seeds; these were identified and signs of damage noted. Species that had ripe fruit that were not eaten by the Black Lemur were also identified, as were fleshy-fruited species that produced little or no ripe fruits during the study. Other frugivores feeding on the fruits of black lemur-dispersed species were also noted. In order to estimate the proportion of tree species, tree trunks, and trunk basal area in the Lokobe Forest dispersed, possibly dispersed, and not dispersed by Black Lemurs, plots were installed in Lokobe's two forest types and the trees they enclosed were identified and their dbh measured. For the slope forest Black Lemurs dispersed 57% of the represented tree species, 71 % of the represented tree trunks, and 73% of the represented trunk basal area. For the ridge forest these values were 49%,76%, and 88% respectively. Only four of the 38 black lemur-dispersed species had fruits that were also eaten by other frugivore species. These results show that the Black Lemur is very important for seed dispersal in Lokobe Forest.