Browsing by Author "Holmes, Sheila Marie"
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Item Open Access Habitat use and population genetics of the black-and-white ruffed lemur (varecia variegata) in a fragmented landscape in southeastern Madagascar(2012) Holmes, Sheila Marie; Johnson, Steig E.I examined the relationship between selective habitat use and population genetic structure of black-and-white ruffed lemurs (Varecia variegata) in the fragmented Kianjavato- Vatovavy landscape in southeastem Madagascar. I calculated ranges for 17 lemurs in two forest fragments (June 2010 - March 2011, 4149 GPS points) and analysed the relationship between microhabitat characteristics and the probability of use of areas, and the extended use of trees within ranges. I genotyped 33 faecal samples for 16 microsatellites, adding 22 individuals from nearby continuous forest Ranomafana National Park. Despite the preferential use of large trees with broad crowns, low elevations, forest interiors, and areas with a large basal area of food species, it appears moderate fragment isolation (< lOOm) is insufficient to disrupt V variegata gene flow. However, larger distances (6km) isolated populations, leading to a population bottleneck and a drop in allelic richness. These results may inform reforestation and management efforts.Item Open Access Sharing Space: Habitat Use and Spatial Relationships of Frugivorous Lemurs in Fragmented Forests(2017) Holmes, Sheila Marie; Johnson, Steig Eric; Gordon, Adam D.; Moehrenschlager, Axel; Rolian, Campbell Paul; Neuhaus, Peter; Henzi, PeterI studied the habitat use and interspecific association patterns of red-bellied, red-fronted, and black-and-white ruffed lemurs at Kianjavato, Madagascar. I also investigated the flexible intraspecific association patterns of black-and-white ruffed lemurs. These studies took place in two forest patches of different sizes and disturbance levels within a largely-deforested landscape. Results sometimes differed across forest fragments, indicating potential impacts of fragment size and/or vegetation structure on habitat use and association patterns. All three species used trees with broader crowns more heavily, underscoring the importance of this limited resource. Fruit availability also influenced ruffed lemur habitat use and subgroup size. This species also showed some avoidance of the forest edge and tended to form larger groups of adults when offspring were present. Both red-bellied lemurs and red-fronted lemurs showed avoidance of ruffed lemur core use areas, though they did not avoid one another spatiotemporally. Red-fronted lemurs actually showed positive spatiotemporal associations with both ruffed lemurs and red-bellied lemurs. This was positively related to the amount of core area overlap between groups, and may have been related to the resources and predators shared by these three species. Currently, spatial avoidance of core areas and small differences in diet may facilitate the coexistence of these three species, though red-bellied lemurs may be limited to more marginal habitat in some cases. Future changes to the forest (i.e., deforestation or reforestation) should be monitored, as they may alter both habitat use and association patterns.