Diversity and distribution patterns of non-volant small mammals along different elevation gradients on Mt. Kenya, Kenya.

Simon Musila,Quan Li,Samson Omondi,Immaculate Muthoni,Richard Yego,Shui-Wang He,James Mathenge,Bin Zhang,Kenneth Otieno Onditi ,Esther N Kioko ,Zhongzheng Chen ,Xuelong Jiang

doi:10.24272/j.issn.2095-8137.2019.004

Abstract

The distribution of small mammals in mountainous environments across different elevations can provide important information on the effects of climate change on the dispersal of species. However, few studies conducted on Afromontane ecosystems have compared the altitudinal patterns of small mammal diversity. We investigated the species diversity and abundance of non-volant small mammals (hereafter ‘small mammals’) on Mt. Kenya, the second tallest mountain in Africa, using a standard sampling scheme. Nine sampling transects were established at intervals of 200 m on the eastern (Chogoria) and western (Sirimon) slopes. A total of 1 905 individuals representing 25 species of small mammals were trapped after 12 240 trap-nights. Abundance was highest at mid-elevations on both slopes. However, species richness and their distribution patterns differed between the two slopes. More species were recorded on Chogoria (24) than on Sirimon (17). On Chogoria, species richness was higher at mid-high elevations, with a peak at mid-elevation (2 800 m a.s.l.), whereas species richness showed little variation on the Sirimon slope. These results indicate that patterns of species diversity can differ between slopes on the same mountain. In addition, we extensively reviewed literature on Mt. Kenya’s mammals and compiled a comprehensive checklist of 76 mammalian species. However, additional research is required to improve our understanding of small mammal diversity in mountain habitats in Africa.

Highlights

Baseline information on biodiversity is important in ecosystem management planning
Measurements were taken for each individual, including lengths of head and body (HB), tail (TL), hind foot (HF), and left ear (EL), as well as weight (WT)
The mean number of species at each elevation was lower on Chogoria (9.00±2.50) than that on Sirimon (9.22±1.30)

Summary

Introduction

Clarifying species distribution provides useful information on ecology, habitat preference, and species replacement (Goodman et al, 1996; Malonza et al, 2018; Stanley & Kihaule, 2016). Studies investigating the relationship between species richness and altitude have yielded diverse patterns (Taylor et al, 2015). Previous studies on non-volant small mammals have observed hump-shaped diversity curves, with the highest richness found at mid-elevations (McCain, 2005). The montane mammal communities of sub-Saharan Africa have been sporadically studied, with research on mountain elevation distribution relatively well documented, including that of the Ruwenzori Mountains (Kerbis et al, 1998), Udzungwa Mountains (Stanley & Hutterer, 2007), and Mt. Kilimanjaro (Mulungu et al, 2008; Stanley et al, 2014). Studies of small mammals along different elevation gradients on Mt. Kenya are lacking

Methods

Results

Conclusion