Changes of Bat Activity, Species Richness, Diversity and Community Composition Over an Altitudinal Gradient in the Soutpansberg Range, South Africa

Changes of bat species composition over altitudinal gradients on northern and southern aspects of the Soutpansberg mountain range, South Africa

“…At Mount Mulanje in Malawi, Curran et al (2012) found an altitudinal pattern of a "low plateau", suggesting a decline of bat species richness starting at intermediate altitudes, with highest species richness at 1220 m. This pattern was significantly correlated with measures of habitat structure and also supported the global climate model of McCain (2007b). In the Soutpansberg Mountains in South Africa, Linden et al (2014) found a decline in species richness and diversity with altitude, as suggested for tropical regions by McCain (2007b). The study also found vegetation type, correlated with altitude, to be the main underlying factor explaining the observed pattern.…”

“…Whereas, a previous study (Linden et al 2014) was conducted in the Luvhondo Private Nature Reserve (LPNR) on the southern aspect of the Soutpansberg, the present study extended the study area to the northern aspect, exactly opposite to the LPNR. As described by Mucina and Rutherford (2006), the habitat types found within the study area are Soutpansberg Mountain Bushveld (SMB), Northern Mistbelt Forest (NMF), Soutpansberg Summit Sourveld (SSS), Makhado Sweet Bushveld (MSB) and Musina Mopane Bushveld (MMB) (Figure 1).…”

“…For this purpose, we extended the study area of Linden et al (2014) to the northern aspect of the mountain range, in order to compare the data from both studies. We also tested the results against the climate model of McCain (2007b).…”

“…To our knowledge, the study of Linden et al (2014) was the first attempt to analyse changes of bat species composition over an altitudinal gradient in South Africa. At Mount Mulanje in Malawi, Curran et al (2012) found an altitudinal pattern of a "low plateau", suggesting a decline of bat species richness starting at intermediate altitudes, with highest species richness at 1220 m. This pattern was significantly correlated with measures of habitat structure and also supported the global climate model of McCain (2007b).…”

“…Based on the assumption of McCain (2007b) that water availability is a main factor in determining the shape of altitudinal distribution in bats, we hypothesise that, in contrast with the more tropical southern aspect which shows a decline with altitude, on the drier northern aspect, the altitudinal pattern of bat species richness should follow a humped shaped pattern with a mid-altitudinal peak in bat species richness. Based on the studies of Linden et al (2014) and Curran et al (2012), we further expect vegetation type and measures of habitat structure, correlated to climate, to be the main variables explaining the distribution of bat species over altitude. We also tested the "mid-domain effect" which specifies that most ranges of species overlap towards intermediate altitudes (the "mid-domain") (Colwell and Lees 2000, McCain 2005, Kryštufek et al 2011).…”