L’écologie de Mungotictis decemlineata dans les forêts décidues de l’ouest de Madagascar

Résumé En

A wild population of the endemic Madagascar mungoose Mungotictis decemlineata was studied in 1974 and 1975 near Analabe, W. Madagascar. Some individuals were «tail-marked » and followed by radio-tracking. Five months were spent in the field at different seasons of the year. Mungotictis decemlineata lives in a dry forest whose primary productivity is highly seasonal, occuring mostly during the rainy period of the austral summer. This Madagascar mungoose is diurnal in habits. The night is spent in tree holes during the wet summer and in ground burrows during the dry winter. Several individuals of the same social group may congregate to spend the night in the same shelter which often varies from day to day. In the absence of old abandonned ant-hills, Mungotictis can dig by itself his own ground burrows. The diurnal activity period is longer during the rainy season than during the winter. Mungotictis is both terrestrial and arboreal. It can climb trees, bear like, up to a diameter of about a foot ; however it usually prefers smaller trunks and vines. The diet is mostly insectivorous. The stapple food, especially in winter time, consists of insect larvae, which they extract from the ground (mostly larvae of Tenebrionid beetles and Heteronychus) or from dead wood (larvae of Cetonid and Elaterid beetles). This insect diet is supplemented, especially in summer, by millipedes, snails, amphibians, lizards and mouse lemurs. Grouphunting of Microcebus murinus and chamaeleons has been observed. Up to 20 g of insect larvae (fresh weight) can be consumed per individual per day. The 22 individuals living in an area of 300 hectares were permanently divided into two stable social units, here called «super-groups», within which the inter-individual social relationships were very variable depending on the season. Broadly speaking adult males and females tended to come together during the summer and to split during the winter into smaller groups. These winter social units were very variable : temporary pairs, maternal family parties, all-male groups or even solitary males. Such a dry-season scattering of the ««super-group» members may be considered as an adaptation to the pattern of distribution of the available food sources. Two-year old juveniles leave their mothers at the time of the breeding season (February and March). Agonistic behaviours were observed both around the winter feeding areas in which insect larvae were plentiful, and, at all times of the year, in the border zone between the «territories » of two adjacent «super.groups».