Spatial and Temporal Habitat Use by GPS Collared Male Cheetahs in Modified Bushland Habitat

Abstract

Cheetahs and other apex predators are threatened by human-wildlife conflict and habitat degradation. Bush encroachment creates one of the biggest forms of habitat change, thus it is important to understand the impact this has on habitat use. We investigated habitat preferences of five male cheetahs in Namibian farmlands degraded by bush encroachment. Cheetahs were tracked using satellite based Global System for Mobile (GSM) collars providing a higher resolution on ranging behavior. We aimed to investigate: 1) habitat characteristics; 2) evidence for habitat selection; 3) temporal activity partitioning; and 4) whether revisits to locations were related to habitat type. There were differences in habitat characteristics, showing that cheetahs were able to utilise different habitats. Fecal pellet counts revealed that warthog, oryx, scrub hare and kudu were most abundant. The cheetahs spent more time in high visibility shrubland, suggesting they selected rewarding patches within predominantly bush-encroached landscapes. The usage in marginal habitat was strikingly influenced by habitat type, with both previously cleared and open vegetated areas showing high proportions in edge use. Individuals exhibited significant temporal activity partitioning, showing peaks between late afternoon and early morning hours. This finding could be key to managing human-wildlife conflict by showing that increased protection such as the use of herders and livestock guarding dogs should be used as mitigation methods to minimize the impact of cheetah specific temporal patterns at all times as defined in this research. Visits to the same locations were not correlated to habitat type; revisits may be dictated by other reasons such as social interaction, prey density or avoidance of other predators. Findings from this study will help build existing knowledge on the effects bush encroachment has on cheetah habitat preference.

Response of woody vegetation to bush thinning on freehold farmlands in north-central Namibia

“…The mean sighting line (57.4 m) in the thinned areas in this study is less than those measured in sparsely vegetated areas preferred by cheetahs reported in other studies 4 , 52 in the same region. The shorter mean sightline in the thinned areas in our study could be due partly to the fact that thinning was carried out conservatively in this area with the aim to retain specific tree/shrub densities rather than the densities that would result from natural disturbances (e.g.…”

“…Vegetation data was collected from April to August 2017. We quantified sighting lines at the subplot level by positioning an observer who crouched 0.65 m aboveground, and measured the initial distance at which objects (human) could not be detected by an observer 4 , 52 . The starting bearing (direction) was random, three other similar measurements were added sequentially at 90° from the previous bearing.…”

Bush Encroachment and Large Carnivore Predation Success in African Landscapes: A Review

“…Hunting Efficiency Bush encroachment alters the predators' hunting grounds [50] (Figure 3a). Search and recognition may be diminished by the decreased sighting visibility that accompanies increased shrub cover, especially for predators that rely on the identification of prey from great distances [15,51]. Greater bush cover may decrease capture success for cursorial predators that are adapted to run by impeding prey chases while enhancing capture for ambush predators that can more easily conceal themselves to employ the sit-and-wait strategy [52,53].…”

“…Previous studies have indicated that male cheetah habitat selection is more strongly influenced by hunting requirements than prey density [55][56][57][58][59]. Muntifering et al [18] and Nghikembua et al [15] tracked cheetahs in north-central Namibia, where bush encroachment poses a threat to ecosystems [60] and identified significantly increased use of open shrubland and grassy areas, where sighting visibility was high. Habitat structure in open areas likely allows greater search and encounter success, as well as potentially providing the cheetah, a cursorial predator, with open areas to increase capture success (Figure 3b).…”

“…The issue is exacerbated in arid and semi-arid ecosystems that are prone to drought and high rainfall variability, such as much of the African continent [2,14]. Evidence is starting to emerge indicating that bush encroachment in African landscapes can alter the hunting habitats of large predators [2], for example by decreasing the availability of habitat edges used by large predators such as the cheetah (Acinonyx jubatus) to visualise and stalk prey [15,16]. Ecosystem effects of bush encroachment, such as increased bush density and altered prey availability, may influence the predation success of carnivores, but concrete evidence and synthesis are lacking.…”