Changing distributions of larger ungulates in the Kruger National Park from ecological aerial survey data

Abstract

Documenting current species distribution patterns and their association with habitat types is important as a basis for assessing future range shifts in response to climate change or other influences. We used the adaptive local convex hull (a-LoCoH) method to map distribution ranges of 12 ungulate species within the Kruger National Park (KNP) based on locations recorded during aerial surveys (1980–1993). We used log-linear models to identify changes in regional distribution patterns and chi-square tests to determine shifts in habitat occupation over this period. We compared observed patterns with earlier, more subjectively derived distribution maps for these species. Zebra, wildebeest and giraffe distributions shifted towards the far northern section of the KNP, whilst buffalo and kudu showed proportional declines in the north. Sable antelope distribution contracted most in the north, whilst tsessebe, eland and roan antelope distributions showed no shifts. Warthog and waterbuck contracted in the central and northern regions, respectively. The distribution of impala did not change. Compared with earlier distributions, impala, zebra, buffalo, warthog and waterbuck had become less strongly concentrated along rivers. Wildebeest, zebra, sable antelope and tsessebe had become less prevalent in localities west of the central region. Concerning habitat occupation, the majority of grazers showed a concentration on basaltic substrates, whilst sable antelope favoured mopane-dominated woodland and sour bushveld on granite. Buffalo showed no strong preference for any habitats and waterbuck were concentrated along rivers. Although widespread, impala were absent from sections of mopane shrubveld and sandveld. Kudu and giraffe were widespread through most habitats, but with a lesser prevalence in northern mopane-dominated habitats. Documented distribution shifts appeared to be related to the completion of the western boundary fence and widened provision of surface water within the park. Conservation implications: The objectively recorded distribution patterns provide a foundation for assessing future changes in distribution that may take place in response to climatic shifts or other influences.

Climate‐related range shifts – a global multidimensional synthesis and new research directions

“…Notably, only a few local studies restricted to tiny ecoregions and thus difficult to spot on the global map ( Fig. The number of reports from tropical and subtropical forests (Pounds et al 1999, Raxworthy et al 2008, Chen et al 2009, Feeley et al 2011, tropical and subtropical grasslands savannahs and shrublands (Hockey et al 2011, Chirima et al 2012, Sirami and Monadjem 2012 and deserts and xeric shrublands (Sinervo et al 2010, Hockey et al 2011) is relatively low, but has recently begun to increase. Evidence in Europe and North America is mainly from Mediterranean woodlands, temperate broadleaved and mixed forests, temperate conifer forests, boreal forests and tundra ecosystems (Fig.…”

Habitat differences do not explain population declines of sable antelope in an African savanna

“…During the 1997 aerial survey, five other sable herds totaling 33 animals were recorded in the area lying between the home range of the Phabeni herd and the ranges of the other four herds that we later fitted with GPS collars (Chirima, Owen‐Smith & Erasmus, ; Supporting Information http://onlinelibrary.wiley.com/doi/10.1111/jzo.12269/suppinfo). By the time of our study, this region was no longer inhabited by sable herds.…”

Spatial ecology of large herbivore populations

“…sable antelope, waterbuck Kobus ellipsiprymnus , hippo Hippopotamus amphibius ), or even isolated range clusters (e.g. roan antelope Hippotragus equinus ; Chirima et al 2012). Some of the smallest antelope appear to be widespread through the park, but are restricted in their local habitat occupation (e.g.…”