Ecology and Interactions of Cape Foxes, Bat-eared Foxes, and Black-backed Jackals in South Africa
Between April 2005 and March 2008, led by Dr Jan Kamler, we studied the relationships among canid species in South Africa, primarily out of concern for declining cape fox numbers. Two sites were chosen: (1) Benfontein Game Farm, which had relatively high jackal numbers; and (2) private sheep farms adjacent to Benfontein, which had virtually no jackals. The overall goal was to compare densities, home ranges, activity, and other behaviors between sites for both fox species.
At total of 74 individual canids were captured and monitored on both sites, including 11 cape foxes, 22 bat-eared foxes, and 15 black-backed jackals on Benfontein, and 8 cape foxes and 18 bat-eared foxes in the sheep farms. Results showed that black-backed jackals had negative impacts on both cape foxes and bat-eared foxes. For example, predation from jackals was responsible for 71% of cape fox deaths, and 67% of bat-eared fox deaths. Black-backed jackals also appeared to negatively affect the home range and spatial distribution of cape foxes, as well as group sizes of bat-eared foxes. Cape foxes clearly avoided jackal core areas, thus cape foxes had to range over larger areas to safely find food in areas with high jackal densities. Additionally, cape foxes established natal dens only when > 2 km from jackal dens, thus there were few places on Benfontein where cape foxes could safely raise litters. This caused cape fox densities to decrease 64% on Benfontein compared to adjacent sheep farms. Ultimately, cape fox and jackal numbers were inversely related across several sites, so higher jackal numbers caused lower cape fox numbers, and cape foxes were completely excluded at the highest jackal densities.
Jackals did not appear to significantly influence movements or numbers of bat-eared foxes. However, group size of bat-eared foxes was 4-5 adults/group on Benfontein, but only 2-3 adults/group on the sheep farms. It appeared that in the presence of jackals, bat-eared foxes stayed in larger groups for better protection against predation. This has important implications concerning disease outbreaks, as the larger group sizes and more overlapping home ranges of bat-eared foxes on Benfontein probably increased their susceptibility to epizootics, which frequently occurred on Benfontein but not on the sheep farms.
Diets on Benfontein overlapped little between jackals and cape foxes (0.34), and jackals and bat-eared foxes (0.20), suggesting competition for food was minimal. The diet of jackals was dominated by ungulates, whereas cape foxes consumed primarily small rodents and insects, and bat-eared foxes consumed primarily termites and fruit. This suggests jackals were killing foxes not for competition over limited food resources, but rather for other reasons such as territorial space.
This research was funded by a Marie Curie Fellowship from the European Commission, Brussels, Belgium, and a Research Fellowship from the Wildlife Conservation Society, New York.
You can view a short (14 min.) documentary of Jan’s research in South Africa here
(copies of papers can be downloaded at: www.janfkamler.com)
Bagniewska, J., and J. Kamler. 2007. Scent-station surveys: instruction manual. Wildlife Conservation Research Unit, University of Oxford, United Kingdom.
Herrmann, E., J. F. Kamler, and N. L. Avenant. 2008. New records of servals Leptailurus serval in central South Africa. South African Journal of Wildlife Research 38:185-188.
Kamler, J. F. 2008. Ear flashing behaviour of cape hares (Lepus capensis) in South Africa. African Journal of Ecology 46:443-444.
Kamler, J. F., and D. W. Macdonald. 2006. Longevity of a wild bat-eared fox. South African Journal of Wildlife Research 36:199-200.
Kamler, J. F., H. T. Davies-Mostert, L. Hunter, and D. W. Macdonald. 2007. Predation on black-backed jackals (Canis mesomelas) by African wild dogs (Lycaon pictus). African Journal of Ecology 45:667-668.
Kamler, J. F., J. L. Fogt, and K. Collins. 2010. Single black-backed jackal (Canis mesomelas) kills adult impala (Aepyceros melampus). African Journal of Ecology 48:847-848.
Kamler, J. F., N. F. Jacobsen, and D. W. Macdonald. 2008. Efficiency and safety of Soft Catch traps for capturing black-backed jackals and excluding non-target species. South African Journal of Wildlife Research 38:113-116.
Kamler, J. F., U. Stenkewitz, U. Klare, N. F. Jacobsen, and D. W. Macdonald. 2012. Resource partitioning among cape foxes, bat-eared foxes, and black-backed jackals in South Africa. Journal of Wildlife Management 76:In press.
Kamler, J. F., T. N. Suinyuy, and W. Goulding. 2008. Cattle egret and common ostrich associations in South Africa. Ostrich 79:105-106.
Klare, U., J. F. Kamler, and D. W. Macdonald. 2011. The bat-eared fox: A dietary specialist? Mammalian Biology 76:646-650.
Klare, U., J. F. Kamler, and D. W. Macdonald. 2011. A comparison and critique of different scat-analysis methods for determining carnivore diets. Mammal Review 41:294-312.
Klare, U., J. F. Kamler, U. Stenkewitz, and D. W. Macdonald. 2010. Diet, prey selection, and predation impact of black-backed jackals in South Africa. Journal of Wildlife Management 74:1030-1042.
Stenkewitz, U., and J. F. Kamler. 2008. Birds feeding in association with bat-eared foxes on Benfontein Game Farm, South Africa. Ostrich 79:235-237.
Stenkewitz, U., E. Herrmann, and J. F. Kamler. 2010. Distance sampling for estimating springhare, cape hare and steenbok densities in South Africa. South African Journal of Wildlife Research 40:87-92.
Stenkewitz, U., B. Wilson, and J. F. Kamler. 2010. Seasonal comparisons of barn owls diets in an agricultural and natural area in central South Africa. Ostrich 81:163-166.