A University of the Free State team has shown that the number of greater kudus living in a reserve can be estimated with DNA extracted from dung samples. The proof-of-concept study took place at Doornkloof Nature Reserve in South Africa's Northern Cape and avoided capturing, tagging or even directly observing the animals.
The method relies on an individual genetic fingerprint. Researchers collect fresh droppings, extract DNA and identify the species, individual and sex. When the same profile appears in successive samples, that genetic recapture can be used in population estimation models. Instead of attaching a device to the animal, the procedure uses a trace left in the environment.
The genetic estimate for greater kudu closely matched the count already available at Doornkloof. That agreement matters because it moves the idea from the laboratory toward a potentially operational tool for reserve managers. The work is regarded as the first South African study to repeatedly sample one wild population and use individual profiles from feces to calculate its size.
A single sample can yield additional information. Beyond distinguishing individuals and sexes, fecal material can be examined for diet, parasites and other indicators of population health. This combination could improve decisions on carrying capacity, habitat condition and management, especially for nocturnal animals or those living in dense vegetation where aerial and visual surveys lose accuracy.
Low disturbance is the method's main environmental and ethical advantage. Teams can collect material after the animal has left, without pursuit, restraint or handling stress. The technique can also reduce risks to researchers and wildlife, although it requires rigorous protocols to locate fresh samples, prevent contamination and recover DNA of sufficient quality.
Greater kudu served as the test species, but the team sees applications for more elusive or threatened animals, including aardvarks, brown hyenas, riverine rabbits, bat-eared foxes and small wildcats. Before broader use, markers, sampling design, costs and accuracy must be validated for each species and habitat because dung detectability and DNA degradation vary.
Researchers have already completed a larger survey across the reserve and are analyzing the results. The next stage must determine whether the procedure remains reliable at greater scale and for populations without a previous count for comparison. If it passes those tests, environmental DNA could give African reserves a less invasive way to produce the data needed to protect hard-to-see biodiversity.
