Giant Thicket Rat (Grammomys gigas)

Mohamed bin Zayed Species project number 172514910

CHANGES IN ELEVATION, IMPACTS ON THE ABUNDANCE & DISTRIBUTION OF GIANT THICKET RAT, ENDEMIC TO MT. KENYA.

The distribution and species richness of small mammal biodiversity around the Mt. Kenya is not properly understood. The Giant thicket rat (Grammomys gigas); a species of rodent in the family Muridae is endangered and endemic to Mt. Kenya. In the Mt. Kenya, human pressure on the ecosystem elevations are being exploited at different rates. Could this differential ecosystem exploitation be affecting the abundance and distribution of the Giant thicket rat? The local people are changing ecosystems more rapidly and more extensively than over any other period. Climate change adds yet another pressure on natural resources leading to biodiversity loss. In an effort to save the Giant thicket rat from the mounting threats, this proposed project aims to; 1. Investigate Giant thicket rat species richness with changes in elevation, 2. Investigate Giant thicket rat abundance with changes in elevation, 3. Determine whether differential ecosystem exploitation in each elevation affects the abundance and the distribution of the Giant thicket rat. Finally, monitor traditional perceptions to the Giant thicket rat & hunting levels. The project will also present the major climate change threats that are specific to the Giant thicket rat as well as opportunities for mitigation and adaptation to safe the species from these threats.The recent assessment by Agwanda, B. indicates that habitat of this species is being deforested for timber, firewood and conversion to agriculture & that more research is required on taxonomy, distribution, abundance, natural history and threats to this species (www.iucnredlist.org). The Giant Thicket Rat being a small mammal is currently faced with imminent extinction and this project endeavours to bring the situation into focus. The Giant thicket rat will be searched in its range of occurrence; monitor elevation changes and impacts on distribution and abundance. Spatially Explicit Capture Recapture Model (SECR) will be used to estimate population density of this species (Efford and Fewster 2013). At every elevation; ten capture grids of 100 traps will be established using Arc Map version 10.2.1, with the trapping points chosen randomly. 100 Sherman’s traps (7.5 X 9.0 X 23.0 cm, HB Sherman Trap Inc); placed at 10M from each other & four 5L bucket pit falls, placed at the centre of the grid at 20M from the centre of the grid. All the Giant Thicket rat captured will be handled with extreme care and identified using Happold (2013) and by comparison with collections at the Mammalogy Section NMK. The Giant Thicket Rat Morphometrics i.e. TL (tail length), HB (length of head and body, HF (length of hind foot), EL (length of left ear), WT (body weight) will be recorded. The maturity/reproductive status checked as illustrated in Gurnell & Flowerdew (1990) i.e. Position of the testes/condition of the vagina and nipples as indicators of breeding status. Males in breeding (testes will be scrotal or abdominal) and if the epididymal gubernacula is externally visible or not; females as sexually active when the vagina is perforated; pregnant (swollen nipples); with pregnancies being identified by palpation (Massawe, et al., 2011; Chekol, et al., 2012).