Due to the elusive character of the cheetahs, it is difficult and time consuming to determine their diet composition by direct observations. Thus, indirect methods are more feasible to conduct. One such method is to identify undigested hairs of prey species in the cheetah’s faeces. Each species has a characteristic pattern of the cuticle and medulla of the hair, thus with the help of a reference catalogue undigested hairs in faeces can be used to determine the consumed prey species by a carnivore. However, the determination of the diet composition by using the number of faeces with hairs of a particular prey species is not straightforward. This is because small prey species have more indigestible hair per kg of meat than large prey species and thus the former/latter would be over-/underrepresented when simply calculating the percentage of faeces containing the prey species. To correct for this bias, correction factors need to be established by feeding captive carnivores in a standardize procedure with different prey species and prey mass.

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We conducted together with our cooperation partners feeding trials with cheetahs and various prey species and prey masses. Using the number of produced faeces for each prey animal, we established two correction factors for two different presentations of diet composition. Correction factor 1 was established to describe the diet composition as proportions of consumed biomass of each prey species, while correction factor 2 was established to describe the diet composition as proportions of consumed individuals of each prey species. Our faecal analyses revealed that cheetahs feed mainly on common herbivore species such as hartebeest roaming on farmland and only rarely kill cattle or other livestock species. Nevertheless, we appreciate that for a farmer, a few losses of livestock can result in a substantial economical loss. See sub-projects “Sparial ecologoy and distribution of free-ranging cheetahs” and “Stakeholder involvement and solution to the farmer-cheetah conflict” for our in-depth research on these topics.

Another possibility to determine the diet composition in an indirect way is the use of stable isotopes, mainly of carbon (C) and nitrogen (N). For example, herbivores feeding on grasses, i.e. C4 plants, have a higher stable C isotope ratio in their muscles than herbivores feeding on browse, i.e. C3 plants. When predators feed on herbivores, stable C and N isotopes ratios of the herbivores integrate into the tissues of the predators and reflect the relative contribution of grazers and browsers to its diet. Together with our collaborators, we determined that cheetah males mainly fed on hartebeest and warthogs, whereas females mainly fed on browsers such as springbok, steenbok and scrub hare. Stable isotopes can also be measured in the breath and our analyses revealed similar results as for the tissues. Further, stable C and N isotopes can be measure in hairs or whiskers, which we did in leopards. Female leopards exhibited a larger isotopic dietary niche widths than male leopards. This might be explained by a more opportunistic feeding of females, most likely of a higher use of small prey species of different isotopic composition.  

The diet has also an influence on fatty acids. Fatty acids provide a source of metabolisable energy, have important functions in hormone production and cellular signaling, and provide structural components in membranes. To understand the pathways of diet composition on fatty acids, we compared with our collaborators fatty acids of free-ranging cheetahs with captive ones in Namibia. There were large differences between the two groups which are likely based on captive cheetahs being feed mainly on exsanguinated muscle meat, whereas free-ranging cheetahs feed on entire prey animals. Assuming that the diet composition in nature represents a balanced and healthy diet, captive cheetahs might need some supplementary components in their diet to keep them healthy in the long run.

Publications reporting on these topics

  • Wachter B, Jauernig O, Breitenmoser U 2006: Determination of prey hair in faeces in free-ranging Namibian cheetahs with a simple method. Cat News 44, 8-9.
  • Wachter B, Blanc A-S, Melzheimer J, Höner OP, Jago M, Hofer H 2012: An advanced method to assess the diet of free-ranging large carnivores based on scats. PLoS ONE 7(6): e38066. Doi: 10.1371/journal.pone.0038066.
  • Voigt CC, Melzheimer J, Thalwitzer S, Wachter B 2013: A breath test to assign carnivore diets to browsers or grazers. Wildlife Biology 19: 311-316. Doi: 10.2981/13-012.
  • Voigt CC, Thalwitzer S, Melzheimer J, Blanc A-S, Jago M, Wachter B 2014: The conflict between cheetahs and humans on Namibian farmland elucidated by stable isotope diet analysis. PLoS ONE 9(8): e101917. Doi: 10.1371/journal.pone.0101918.
  • Hudson-Lamb GC, Schoeman JP, Hooijberg EH, Heinrich SK, Tordiffe ASW 2016: Reference intervals for selected serum biochemistry analytes in cheetahs (Acinonyx jubatus). Journal of the South African Veterinary Association 87(1), Art. #1316, 6 pages. Doi: 10.4102/jsava.v87i1.1316.
  • Tordiffe ASW, Wachter B, Heinrich SK, Reyers F, Mienie LJ 2016: Comparative serum fatty acid profiles of captive and free-ranging cheetahs (Acinonyx jubatus) in Namibia. PLoS ONE 11(12): e0167608. Doi:10.1371/journal.pone.0167608.
  • Schmidt-Küntzel A, Wultsch C, Boast LK, Braun B, van der Weyde L, Wachter B, Brummer R, Walker EH, Forsythe K, Marker L 2018: Mining black gold – insights from cheetah scat using noninvasive techniques in the field and laboratory: scat-detection dogs, genetic assignment, diet and hormone analyses. In: Cheetahs: Biology and conservation. Marker L, Boast L, Schmidt-Küntzel A (eds), Academic Press, San Diego, USA. 437-446. Doi: 10.1016/B978-0-12-804088-1.00031-9.
  • Voigt CC, Krofel M, Menges V, Wachter B, Melzheimer J 2018: Sex-specific dietary specialization in a terrestrial apex predator, the leopard, revealed by stable isotope analysis. Journal of Zoology 306: 1-7. Doi: 10.1111//jzo.12566.