Inventaire des delphinidés dans la région Est de la Tunisie (Teboulba) : suivi de la répartition spatiale, démographie et éthologie

Abstract

Little effort has been made to monitor populations of delphinids along the east coasts of Tunisia, considered to be a very productive coastal ecosystem
conducive to the establishment of cetaceans. This work is a first contribution to the study of the dolphinids in this. The main results show that the prospected area shelters two species of delphinidae occupying two different ecotypes. 91 groups of Tursiops truncatus, 9 groups of Stenella coeruleolba and 3 mixed groups of Stenella and Tursiops were observed. The group size of Tursiops was smaller than those of Stenella. The group size of these two species varies with depth, distance from the coast and the occurrence of immatures. The two species occupy the study area differently, where Tursiops spend more time on feeding and depredation activities. On the other hand, Stenella takes advantage of the study area to socialize, travel and feeding. All these results allow us to
assume that the eastern zone of Tunisia can be considered as areao of interest and even an important marine mamals area dor these two dolphins.