The diet of Caracal (Caracal caracal) in the southern Free State
Tuesday, 1st December 2015
MSc Thesis, University of the Free State, 2015
Caracal Caracal caracal is a damage-causing predator in rangeland ecosystems of southern Africa, with the southern Free State being one of the most severely impacted small stock areas. Available literature indicate that these cats usually prey on the most abundant prey groups, but are also opportunistic and take small stock, especially during lambing seasons.The aim of this study was to define the diet of caracal over a 13 month period through scat analysis in a small stock area and to discuss its prey-niche overlap and sharing with the three most common sympatric carnivores-black backed jackal Canis mesomelas, Cape grey mongoose Galerella pulverulenta and yellow mongoose Cynictis penicillata. The study site was described as a productive ecosystem and characterised by a perse number of prey species. Prey availability was determined on a number of transects (driven and walked) and through numerous observations of birth peaks/the presence of young.
Results show that caracal fed predominantly on Mammalia prey (94.74 percentage ;occurrence, %Occ.; 93.40 percentage volume, %Vol.). Prey items that made the most notable contributions to caracal diet were Lagomorpha (28.5%Occ.; 28.0%Vol.), rock hyraxProcavia capensis (17.5%Occ.; 17.3%Vol.), and springhare Pedetes capensis (15.2%Occ.;15.2%Vol.) and domestic sheep Ovis aries (13.6%Occ.; 13.6%Vol.). Prey items that made the most notable contributions to black- backed jackal diet were Muridae (34.43%Occ.;9.83%Vol.), Lagomorpha (19.94%Occ.; 16.98%Vol.), springbok Antidorcas marsupialis (13.92%Occ.; 12.92%Vol.), sheep Ovis aries (9.09%Occ.; 8.24%Vol.) and mountain reedbuck Redunca fulvorufula (9.82%Occ.; 9.42%Vol.).
The current study showed that caracal was more of a specialist than black-backed jackal, with the latter utilizing the widest prey spectrum. Both caracal and black- backed jackal fed opportunistically in this study, and their diets included a large proportion of natural prey. The diet of caracal and black-backed jackal included more mammal and less invertebrate prey than that of Cape grey mongoose and yellow mongoose.Of the four predators studied, black-backed jackal diet was the most perse (widest niche breadth), followed by Cape grey mongoose, caracal, and yellow mongoose diet the least perse. The two larger carnivores, caracal and black-backed jackal, utilised their prey items with higher evenness than the two mongoose species.
Highest niche overlap was observed between caracal and black-backed jackal (1.0), and between Cape grey mongoose and yellow mongoose (0.9). Moderate niche overlap was observed between caracal and Cape grey mongoose, and between black-backed jackal and Cape grey mongoose (both 0.6; smallest overlaps were between caracal and yellow mongoose (0.3), and black-backed jackal and yellow mongoose (Lepus spp. Remains in caracal scats did not correlate with hare monthly abundance (r=0.6; p=0.09), but followed the same general trend. The results suggest that caracal fed on the most abundant prey and opportunistically exploited peaks in prey abundance. Both caracal and black-backed jackal preyed markedly on sheep during the two lambing seasons (March to April and September to October). Black-backed jackal predated less on this prey item than caracal, but predated, more than caracal, on (also economically important) springbok. Both caracal and black-backed jackal were, therefore, damage causing predators in the study area, but also played an intricate role in the ecosystem in that they regulate prey populations and may benefit syntopic carnivores through, for example, carrion provision. Caracal and black-backed jackal may also serve as regulators of prey species that are also potential damage-causing animals (e.g. rodents destroying crops and carrying disease, hyrax competing for forage with sheep, and molerat tunnels causing damage to tractors and plows). Although the current research was a descriptive ecological study of caracal diet in a rangeland ecosystem, and not a management focused project, it nevertheless provided information that can benefit farmers, conservation authorities and the government sector in the quest to address the sensitive issues of predator control and ecosystem conservation on rangelands characterised by major small stock losses.