The Sahamalaza sportive lemur (Lepilemur sahamalazensis) has recently been described based on genetic and morphometric data (Andriaholinirina et al. 2006). Since it is recognized as a good species, the Sahamalaza sportive lemur has been listed as Critically Endangered (CR A4cd), with inclusion on the World's Top 25 Most Endangered Primates 2006 - 2008 (Mittermeier et al. 2007). L. sahamalazensis is the first Lepilemur, and the first nocturnal lemur, to be included on this list. Taking into account their limited distribution, the small extent of remaining forest cover, as well as an average of 2.8 individuals found per hectare by Ruperti (2007), there are probably around 3,000 individual L.sahamalazensis remaining in their natural habitat. Although the range of this cat-sized, nocturnal primate is not precisely known, it is probably limited to the Sahamalaza Peninsula in northwestern Madagascar (Olivieri et al. 2007). This area has experienced rapid deforestation and habitat destruction over recent history. Of particular importance for the continued survival of the Sahamalaza sportive lemur is the protection of primary forests, though secondary forests do not provide ideal habitats for this species, which requires a high density of large trees, an abundance of vegetation tangles, tree holes and food plants, as well as adequate canopy cover (Ruperti 2007). Additionally, L. sahamalazensis is easy and defenseless prey because of its sleeping sites and therefore heavily hunted. The combination of a very limited range containing only little and rapidly decreasing suitable habitat with a high hunting pressure makes this species especially vulnerable (Olivieri et al. 2007). The main objective of the proposed project is to assess the impact of habitat degradation and fragmentation on key aspects of Lepilemur sahamalazensis behaviour (specifically antipredator behaviour, acoustic communication and social behaviour), to directly inform future conservation efforts for this species. A second objective is to establish range boundaries for this species in relation to neighbouring species L. mittermeieri and L. dorsalis. Additionally, this project contributes to sustaining a research presence in the UN Biosphere Reserve and National Park on the Sahamalaza Peninsula, which will continue to enhance public awareness of the ecosystem and will assist long-term conservation and research efforts for this species and its habitat.