[Lemurs of Madagascar. Tests on evolution of primate communities]

The flora and fauna of Madagascar evolved rather independently from the African mainland. In contrast to other oceanic islands, Madagascar is large enough to house most major components of tropical ecosystems, allowing tests of evolutionary hypotheses on the level of complete communities. Taking lemurs, the primates of Madagascar, as an example, evolutionary hypotheses correctly predict the organization of their community structure with respect to ecological correlates. Lemur social systems and their morphological correlates, on the other hand, deviate largely from the typical mammalian pattern. Thus, the traditional hypotheses of behavioral ecology, based solely on resource distribution and predation pressure, are insufficient to explain the existing variability in lemur social systems. Other factors, such as activity patterns and avoidance of infanticide, may be equally important. Due to interspecific variation in these characters, lemurs offer the unique opportunity to determine the relative importance of these factors for the evolution of social systems.