Organisation du peuplement de marsupiaux en Guyane Française

Résumé En

The structure of the marsupial communities was investigated from 1984 to 1987 in different forest types of French Guiana. The mature forest community of the Piste de Saint-Elie (PSE) study site was studied at regular intervals for 22 months by direct observation and trapping, allowing a detailed comparison to be made with the Cabassou (Cab) secondary forest community previously studied by P. Charles-Dominique et al. (1981), and with other sites less thoroughly investigated. Nine marsupial species (Didelphidae) coexist in the PSE mature forest, ranging in weight from 20 to 1 100 g. All share the habitat, both vertically (ground level, understorey and/or canopy) and horizontally (well drained vs. hydromor- phic soils, watercourses) (Tables II, III). The eight terrestrial and arboreal species are found in pairs, in which both species are morphologically and ecologically comparable, but one is common and the other is rare (Table VII). Population densities appear to be low, even for the most abundant species. In contrast, species richness is lower in secondary forest (six species at Cabassou), and the density of the most common species is higher. Only one species pair is remaining, through the disappearance of most rare species. A review of the scanty data available for French Guiana, and of those scattered in the literature, suggests that those marsupial species which are rare and found only in mature forest are habitat specialists, whereas the second-growth species are habitat generalists. However, such a tentative conclusion needs to be supported by further field work. Didelphis albiventris is reported for the first time from French Guiana (PSE).