Shivan Parusnath MSc project (WITS, TUT & EWT)

AIMS

  1. Quantify the relationship between the number of occupied burrows and population density across different habitat types.
    Visual counts are often inaccurate and difficult to conduct when working with elusive animals. Indirect observational methods may thus be employed to estimate population density in such cases (Beck-King et al., 1999). Counting burrows has proven to be an accurate method of estimating population densities in elusive burrowing animals such as crabs (Govender and Rodrigeuz-Fourqet, 2004), tortoises (McCoy and Mushinsky, 1992), rodents (Beck-King et al., 1999) and other small mammals (Boonstra et al., 1992). By comparing visual counts of Sungazers to burrow density counts at sample sites across the different habitat types within the distribution, a comparative technique will be developed to accurately estimate population density using burrow counts. This technique will be more efficient and more appropriate than direct counts of lizards. Fieldwork will take place from December 2013 to April 2014. Sungazer activity peaks in spring and the early summer months (van Wyk, 2000).
  2. Quantify temporal change in population density at previously surveyed sites (31, 20, 17, and 3 years ago).
    Several studies have previously assessed Sungazer populations at varying levels of detail, ranging from distribution-wide surveys (de Waal, 1978) to site-specific studies (McIntyre, 2006). By repeating the research protocol employed by each researcher in the same areas, Shivan will be able to assess the change in population density over several time scales. This information will allow Shivan to assess the level of overall change in Sungazer populations over the past three decades, and will assist in conducting an IUCN reassessment.
  3. Quantify the current area of occupancy and population density in the distribution.
    Using the burrow counting technique explained above, Shivan will measure Sungazer population density in different habitat types within the distribution. If there are different Sungazer: burrow ratios for each habitat type, the relevant ratios can be applied to the habitat type to which it corresponds. Due to the intense fragmentation of Sungazer habitat throughout the distribution and the uncertain implications of edge effects for the species, habitat edges and interiors will be sampled. A gradient of population densities within habitat types can then be quantified.
  4. Quantify the relationship between different land management practices and population density (Conduct an IUCN Red List Assessment).
    Based on the population density measures for each habitat type quantified in the section above, I will be able to estimate population densities across the distribution for each habitat type. This will be done by overlaying population densities and recent landcover maps, and this will allow for an accurate estimation of current occurrence and population densities across the distribution. Further ground-truthing will be conducted to verify the accuracy of the population density scale developed. These data will then be used for predicting future trends of agriculturally driven habitat destruction and associated S. giganteus population loss in those areas. By combining these results with those from section two, a population viability analysis can be conducted for the species. Using all of the collected data, an IUCN reassessment for the species can be conducted.
  5. Identify areas most suitable for the conservation of S. giganteus.
    By assessing distribution-wide population densities, Shivan will identify, with the aid of computer-based GIS, areas that will most benefit from protection against anthropogenic interference. Criteria for these areas will involve intact land supporting contiguous populations and corridors, sites with suitable buffer zones and most importantly, healthy populations of Sungazer’s.