Leopard scats are also collected for dietary analyses. As they serve as territory markers for leopards using the scats scent, care is taken to collect only half the scat. These scats are used to determine leopard diet. Leopard scats have been collected opportunistically since 2004.
Scats are identified as belonging to leopards on one or more of the following criteria:
- Scat diameter >20mm;
- Presence of leopard spoor or marking where the scat was collected; and
- The scat contained leopard hair ingested through interspecific killing or grooming scats <20mm diameter are discarded unless leopard hair was present.
- Often large bone fragments in scats
Dried scats are soaked in formalin, washed and the hair separated from other remains before analysing. Hairs are identified from the cuticular hair scale pattern and compared to a reference collection macroscopic features, such as hair length and colour aided identification, as did any remains of bone fragments, feet and hooves. Smaller rodents are more difficult to identify to species level, although some can be identified by teeth found in the scats.
What do Cape leopards eat?
Leopard diet in the Cederberg and Gamka Mountains consisted largely of small- (1-10 kg) and medium-sized (10-40 kg) mammals. Rock hyraxes (Procavia capensis) and klipspringers (Oreotragus oreotragus) were key prey items.
In the Cederberg we have found 78% of leopard diet to consist of dassies and klipspringer by analysing scats and finding most of the larger kills made. This is very much what we found using scat analyses. The kills are found by identifying groups of GPS points with little separation in time and space. If for example, we find 15 GPS locations, taken 3 hours apart, all within a 50m radius, we would expect to find a klipspringer-sized antelope killed there. The longer a leopard stays at a kill/feeding site, the bigger the prey item is. Small prey such as small rodents cannot be found this way as these would be "fast food" for leopards. However, our work has shown that the little things constitute very little of what leopards need to survive.
In terms of regional variation in leopard diet, there was a significant difference in the average weight of prey utilised in the Cederberg and Gamka Mountains. Despite the importance of prey availability of suitable size, their flexibility in terms of prey size utilization reflected their ability to switch to smaller prey to fulfil their dietary requirements, when prey is limited.