de Namoroka National Park. They are most commonly found in forests near rivers and ponds. The northern giant mouse lemur is found in isolated forest patches along the northwest coast in both the more humid Sambirano valley and Sahamalaza Peninsula, as well as the Ampasindava Peninsula. Its range extends from the Maeverano River in the south to the Mahavavy River in the north. The new population reported by the WWF in 2010 is found in the gallery forests of Ranobe near Toliara in southwestern Madagascar. Behavior Giant mouse lemurs were first studied in the wild by Petter and colleagues in 1971. His observations were secondary to his primary research interest, the fork-marked lemurs north of Morondava. Both northern and southern populations were studied intermittently between 1978 and 1981, and in 1993, long-term social and genetic studies began in Kirindy Forest. Behavioral studies of captive individuals have also been performed at the Duke Lemur Center (DLC) in Durham, North Carolina during the 1990s. Population density and territory Before the recognition of more than one species, differences in population density were noted between southern forests like Kirindy and northern forests near Ambanja. Later, it was recognized that Coquerel's giant mouse lemur was found in lower densities than the northern giant mouse lemur. The former range between 30 and 210 individuals per square kilometer (250 acres), with lower densities in open areas of the forest, while the latter has been recorded with 385 to 1,086 individuals per km2. However, in the case of the northern giant mouse lemur, populations were found in more isolated forest fragments and it is thought that their consumption of introduced cashew and mango help sustain these higher populations. According to studies of Coquerel's giant mouse lemur, home ranges of both sexes vary from with frequent overlap, particularly on the periphery of their range. Individuals most heavily use and aggressively defend a smaller core area within their range. Individuals can have up to eight neighbors. Home ranges of males tend to overlap with those of both females and other males, and typically expand to four times the size during the mating season. Female home ranges show no variability in size, and can remain stable for years. At Kirindy Forest, genetic studies showed that the home ranges of related females tend to clump closely together, while unrelated males may overlap their range, suggesting male dispersal and migration is responsible for