This study was conducted during a period of 16 days (April 10 to April 26, 2011) at the Enashiva Nature Refuge in Northern Tanzania. It was a modified repeat study, using the same methodologies of a mammal survey conducted in November 2009, however this study only focused on occurrence and distribution of predators in the highest trophic level and accounted for reptile and birds, in addition to mammals. Based upon the findings of the November 2009 study, it was hypothesized that the woodland would have the highest predator species richness. This hypothesis was supported by the data; the woodland habitat had the highest alpha richness with a value of 20. All of the habitats were very diverse and the species diversity of Enashiva as a whole was also very high with a value of 0.884. The five different habitat classifications of Enashiva were fairly unique, with the grassland and woodland habitats sharing the highest number of common species. A simultaneously conducted survey on mammals below the highest trophic level found the highest abundance of herbivores in the grassland, which may explain the higher similarity between the grassland and woodland as predators may travel between the woodland to rest and the grassland to hunt. The observed distribution of mammalian predators was consistent with scientific literature on the topic. Furthermore, the survey of mammals in the lower trophic levels found the highest abundance of Thomson’s gazelle, which Leighton-Jones (2002) found to be the only common prey hunted by all lions, leopards, hyenas, and cheetahs. This is important because a high, stable population of Thomson’s gazelles in Enashiva could potentially increase the populations of resident predators as the resource base available to them expands, creating a more stable environment. Viable predator populations play an important role in drawing tourists to the refuge as well as in the overall conservation of the savanna ecosystem: by maintaining populations of species in the lower trophic levels, predators inherently maintain stability within the trophic levels, by preventing trophic cascades, and maintaining an intermediate level of pressure on the resource base. Additionally, much of the research on carnivores in the savanna has only been conducted on vulnerable species, such as cheetahs, but there has not been a strong focus on carnivores as a whole, especially in recovering conservation areas, so this study is important in order to help contribute to the existing knowledge on the topic.
Animal Sciences | Ecology and Evolutionary Biology
Bowles, Adrienne Fisk, "Predators of Enashiva: A Survey of Occurrence & Distribution" (2011). Independent Study Project (ISP) Collection. 986.