Sitatunga population ecology and habitat use in central Uganda

  • Author / Creator
    Warbington, Camille H
  • Effective wildlife management involves understanding the population status and habitat of the species in question, as well as human interests in management decisions. Human dimensions are complicated - African wildlife topics often spark international interest in addition to local concerns. Most African countries surpass those in the global north in the amount of habitat under protection and funds allocated to conservation. Trophy hunting, while controversial, provides much needed conservation funds and provides incentives for local communities to conserve wildlife and habitat. Due to the various human interests involved, the African Wildlife Consultative Forum (AWCF) acts to bring stakeholders together to address emerging issues and collaborate on solutions. As an initiative based in Africa, AWCF positions Africans to take the lead in conserving their resources.
    Sitatunga is a wetland-dependent antelope species endemic to sub-Saharan Africa. Due to the difficulty of working in papyrus marshes, information about sitatunga populations and habitat use are sparse and often conflicting. Adult male sitatungas are sought by trophy hunters, thereby providing an incentive to conserve wetlands. Nevertheless, wetlands are decreasing in Uganda, spurring concerns of barriers to dispersal. I used spatial mark-recapture methods and the time in front of the camera (TIFC) method to estimate density of sitatunga in the Mayanja River area of central Uganda. I used 29 camera traps and observation platforms in and around the wetlands, observing openings in the papyrus. I recorded over 900 encounters with sitatunga during the study. The analysis shows that sitatunga are heterogeneous in terms of movement, with one group moving 25 times farther than the other group. The estimated population density declines over the three years of the study, from 22 / km of river (95% CI 17 – 26) to 7 / km of river (95% CI 4 – 9). The results also show that TIFC density estimates are comparable to those from spatial capture-recapture methods, reinforcing the estimates of density. Since TIFC does not have the same assumptions that spatial methods do, TIFC will be useful for species that do not conform to spatial mark-recapture model requirements. Population genetics can reveal additional information about the sitatunga population viability and habitat connectivity, so I analyzed DNA samples from adult male sitatunga. Results show that this population is not reproductively isolated, indicating wetland connectivity at a larger scale.
    Using camera traps, I analyzed space use of the ungulate assemblage in the study area, which included domestic cattle. I placed cameras in forests, shoreline wetlands, and interior wetlands. I compared the proportion of days with a detection of the species in three habitat types between different hydrologic conditions in the river – high, normal, and low water. Sitatunga are unique in the ungulate community in that they use remote wetlands consistently, regardless of water level. In the forest habitat, all species except sitatunga and warthog show an increase in the proportion of days with a detection over time, regardless of water levels. Even though the intensity of use of forests increases for most species, I expect that dietary and temporal activity differences allow for coexistence in this community, including the novel competitor.
    Sitatunga move more than predicted, have high habitat connectivity, and high fidelity to wetland vegetation. Taking these results together, I suggest that this population of sitatunga is not in decline as density results indicate. Instead, sitatunga are relocating activity centers to areas outside my trapping array or to closed papyrus, where I am unable to detect them. Population density and genetic mixing indicate that this population of sitatunga is secure and there is no conservation concern, although clearly wetlands must be conserved to ensure population persistence.

  • Subjects / Keywords
  • Graduation date
    Fall 2020
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
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