Neam, Kelsey Dillon (2015-08). The Spatial Ecology of a Dispersal Limited Mammal on a Mosaic Landscape. Master's Thesis. Thesis uri icon

abstract

  • As human population, food consumption, and the demand for forest products continue to rise, the pressures of land use change on biodiversity are projected to intensify. In tropical regions, countryside habitats and conventional agricultural practices that retain abundant tree cover and a structurally complex canopy may provide habitats and landscape connectivity for many taxa. This research aimed to assess how the spatial distribution of a dispersal-limited mammal, the brown-throated sloth (Bradypus variegatus), is shaped by differences in the structure and configuration of countryside habitats in Costa Rica, using a multi-scale framework. I conducted two studies to better understand the spatial ecology of brown-throated sloths, and identify specific conservation opportunities for the species. First, data on sloth occurrence was collected from line-transect surveys within countryside habitats (i.e., plantations and mixed-use areas). Subsequently, I developed a density surface map to pinpoint hotspot areas of brown-throated sloths. Second, I measured characteristics of the habitat surrounding sloth presence and absence sites at the local scale (tree height, canopy cover, basal area) and at three broader scales (patch area, shape, degree of isolation) using ArcMap 10.2 and FRAGSTATS 4.2. At the local scale, results indicated that sloths were more likely to be present in structurally complex habitats, specifically areas that were heterogeneous in tree height and basal area. Even within a given habitat type, sloths preferred more complex areas over homogenous areas. At the broader scale, sloths appeared to prefer habitats that encompassed high proportions of secondary forest and those that were nearby large tracts of forest (>=10 ha). The brown-throated sloths in this study seemed to be able to adapt to the disturbed and fragmented environment by utilizing countryside habitats, specifically riparian forests, tree plantations and mixed-use areas. While there is no substitute for the resources and ecosystem services provided by forests, the management of countryside habitats should also be a priority because of their potential to conserve brown-throated sloths, and other taxa throughout the Neotropics. To locally promote the use of countryside habitats by brown-throated sloths, property owners should retain patches of secondary forest and incorporate more structurally complex vegetation into their lands.
  • As human population, food consumption, and the demand for forest products continue to rise, the pressures of land use change on biodiversity are projected to intensify. In tropical regions, countryside habitats and conventional agricultural practices that retain abundant tree cover and a structurally complex canopy may provide habitats and landscape connectivity for many taxa. This research aimed to assess how the spatial distribution of a dispersal-limited mammal, the brown-throated sloth (Bradypus variegatus), is shaped by differences in the structure and configuration of countryside habitats in Costa Rica, using a multi-scale framework.

    I conducted two studies to better understand the spatial ecology of brown-throated sloths, and identify specific conservation opportunities for the species. First, data on sloth occurrence was collected from line-transect surveys within countryside habitats (i.e., plantations and mixed-use areas). Subsequently, I developed a density surface map to pinpoint hotspot areas of brown-throated sloths. Second, I measured characteristics of the habitat surrounding sloth presence and absence sites at the local scale (tree height, canopy cover, basal area) and at three broader scales (patch area, shape, degree of isolation) using ArcMap 10.2 and FRAGSTATS 4.2. At the local scale, results indicated that sloths were more likely to be present in structurally complex habitats, specifically areas that were heterogeneous in tree height and basal area. Even within a given habitat type, sloths preferred more complex areas over homogenous areas. At the broader scale, sloths appeared to prefer habitats that encompassed high proportions of secondary forest and those that were nearby large tracts of forest (>=10 ha).

    The brown-throated sloths in this study seemed to be able to adapt to the disturbed and fragmented environment by utilizing countryside habitats, specifically riparian forests, tree plantations and mixed-use areas. While there is no substitute for the resources and ecosystem services provided by forests, the management of countryside habitats should also be a priority because of their potential to conserve brown-throated sloths, and other taxa throughout the Neotropics. To locally promote the use of countryside habitats by brown-throated sloths, property owners should retain patches of secondary forest and incorporate more structurally complex vegetation into their lands.

publication date

  • August 2015