Le rôle disséminateur des éléphants en forêt de Taï, Côte d’ivoire

Abstract

Elephant droppings have been collected over a whole year in the mature rain forest of Tai, Ivory Coast, and their seed content studied. The seeds of 37 species of trees and 5 species of herbaceous plants have been identified. Out of 37 tree species whose fruits are consumed by elephants in the study area, only seven are known to be also dispersed by monkeys and birds. Marsularia acuminata is eaten throughout the year. Two other species, Parinari holstii and Sacoglottis gabonensis are taken as food in large numbers at certain times of the year only ; their seeds can then make up half the dry weight of the droppings. The germination rate of seeds recovered from elephant droppings is similar to that of mature seeds taken out of intact fruits. However germination is more rapid and seedlings sprouting out of elephant droppings appear healthier. The characteristics of the fruits eaten by elephants are described ; three main categories are distinguished. In the mature rain forest of Western Ivory Coast, fruits appear to represent a major part of elephants’ diet. The role of these Ungulates in the long range dispersal of trees seems to be paramount. Out of 71 species of trees of the Tai forest whose seed dispersal mechanism is known, 21 (29.6 %) are dispersed by elephants.