Landscapes in Madagascar. Travis Steffens PhD Candidate Department of Anthropology University of Toronto

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1 Biogeographic Patterns Affecting Lemur Species Richness and Occurrence in Fragmented Landscapes in Madagascar. Travis Steffens PhD Candidate Department of Anthropology University of Toronto

2 Habitat loss and fragmentation are two of the greatest threats to primate populations in Madagascar. Since the 1950's Madagascar has lost over 50% of its forest. The western deciduous tropical dry forests have lost even more. The resulting landscape consists of fragments of habitat that vary in size and distance from continuous forest. Habitat fragmentation is the splitting up of habitat into smaller patches with increasing distance from one another. While habitat loss is simply the overall reduction in habitat in an area. Habitat fragmentation necessarily includes habitat loss but habitat loss does not have to be the result of habitat fragmentation. In Madagascar there are aproximately 100 lemur species all of which are mainly arboreal. Because all lemur species are mainly arboreal habitat fragmentation is a major threat to all aspects of primate behaviour, ecology and distribution. Various models have been proposed to investigate the impact of habitat loss and fragmentation both at the community and species level. I have chosen to test three main models to he explain how lemur species richness and occurrence are impacted by habitat loss and fragmentation. The first is the species-area relationship, this relationship predicts that the number of species will increase as habitat size increases. The second is island biogeography theory (IBT). Adding to the species-area relationship IBT incorporates a concepts of isolation. like the species-area relationship IBT suggests that islands (in the strict sense or habitat fragments) with more area will have more species then habitats with smaller area because species have lower probabilities of extinction in larger areas than smaller. In addition to the species-area relationship IBT suggests that increasing distance of an island or fragment from the mainland (or continuous forest in the case of habitat fragments) results in a reduced chance a species will colonize an island/fragment. Therefore IBT predicts that large close fragments will have more species than large far fragments and that small close fragments

3 will have more species than small far fragments. Third is the mainland-island metapopulation theory (MT). A metatpopulation is a collection of separate local populations (a collection of breeding individuals within a species) connected via dispersal between the local populations. This theory is similar in some respects to IBT but instead of focussing on the community level (ie. multiple species) MT focusses on individual species. In MT a population occupying a large fragment have a lower probability of local extinction than in a smaller fragment and fragments that are further from continuous forest are less likely to receive immigrants than closer fragments. This is the first project to investigate these models using lemur species and the first to incorporate all three using primates. To determine the impacts of habitat fragmentation on lemur species richness and occurrence I found two landscapes with multiple habitat fragments of varying size and distance from continuous forest. One of these landscapes was studied during phase one of my project between June and November 2011, funded by the Explorers Club Grant. To determine lemur species richness and occurrence I used standard line transect methods. I cut line transect through longest path that ran through the center of each fragment. I conducted between survey walks on each transect during the day and night for a total for surveys of each transect. If a individual was observed during a survey I recorded the observer distance to the individual, the angle between the individual and the transect, species, the height of the individual, group size, group spread, activity, tree height, and I recorded the location of the observation using a GPS. If it was possible I also recorded the perpendicular distance between the transect and the individual and the position of the perpendicular sighting. If an species was observed in a fragment it was considered present if after at least 12 surveys during the day for diurnal species and 12 during the

4 night for nocturnal species a species was not observed it was considered absent. The fragments were originally identified using satellite imagery and later we measured area on the ground by walking the perimeter of each fragment using a hand held GPS device to record the track and later calculate the area in geographic information system software. The study site was located in NW Madagascar on the western side of Ankarafantsika national park. The park consists of mainly continuous dry deciduous forest and along the periphery a mix of forest fragments surrounded by a matrix of savannah grassland. There are a total of eight lemur species found within the park including Propithecus coquereli, Eulemur fulvus, Eulemur mongoz, Cheirogaleous medius, ravelobensis, M. Murinus, Lepilemur edwardsii, and Avahi occidentalis. Results I found six of the eight total species including: Propithecus coquereli, Eulemur fulvus, Cheirogaleous medius, ravelobensis, M. Murinus, and Lepilemur edwardsii. I did not find any specimens of Eulemur mongoz or Avahi occidentalis. Larger fragments had more species than smaller fragments. However, in initial observations distance to the continuous forest does not appear to impact species richness. Table 1. Occurrence of lemur species in 42 fragments in northwest Madagascar. Transect Number murinus ravelobensis Propithecus coquereli Eulemur fulvus Lepilemur edwardsii Cheirogaleus medius 1 Y Y Y Y Y 2 Y Y Y Y Y 3 Y Y Y Y Y Y 4 Y Y Y Y 5 Y Y Y Y 6 Y Y Y Y 7 Y Y Y

5 Transect Number murinus ravelobensis Propithecus coquereli Eulemur fulvus Lepilemur edwardsii Cheirogaleus medius 8 Y Y Y Y 9 Y Y Y 10 Y Y 11 Y Y 12 Y Y Y 13 Y Y 14 Y Y 15 Y Y 16 Y Y 19 Y 20 Y Y Y Y 23 Y Y 24? Y 25 Y 26 Y Y 27 Y Y 28 Y Y 29 Y Y Y Y 32 Y Y 33 Y Y 34 Y Y Y 35 Y Y 36 Y Y Y Y 39 Y Y 40 Y Y 41 Y Y 42 Y