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Lions May Be Targeting Giraffes with Skin Disease

A new study by a team at WildCRU has explored potential connections between lion predation and Giraffe Skin Disease (GSD). This is an emergent disease of presently unknown causes, which has been found to affect giraffes both in the wild and in captivity. The disease manifests as large flaky skin lesions that appear to irritate and itch affected giraffes.

Though detected across the range of giraffes, a hotspot for GSD is in Ruaha National Park, Tanzania, where 85% of the giraffe population has this disease. In that same national park, biologists with the Ruaha Carnivore Project (now Lion Landscapes) have also found that lions appear to prey on giraffes relatively frequently. Giraffes are a large and formidable prey species that can easily injure a lion with a well-placed kick. Given these defense mechanisms, and the fact that a variety of other prey species exist in Ruaha, it was not clear why lions seem to be targeting giraffes.

This new study, led by Dr. Arthur Muneza, evaluated whether the incidence of GSD affected lion predation of giraffes in Ruaha. As the GSD lesions are located on the legs of giraffes in Ruaha, the hypothesis was that giraffes with GSD might be less able to evade lion hunting attempts. To explore this hypothesis, the team followed lions to estimate the rate at which giraffes were targeted and conducted giraffe surveys to detect evidence of previous lion hunting attempts, indicated by missing tails and claw marks on the back of giraffes. They found that giraffes, among 16 different prey species detected as pursued by lions, were killed most often by lions (27%, n = 171 of 641). The authors also found that lion marks, which provided the evidence of a previous lion hunting attempt, were more common among giraffes with severe GSD. This research does not definitively identify that giraffes with GSD are more vulnerable to lion predation, but it does suggest that there may be a mechanistic link. It is presently unclear whether GSD directly reduces the survivability of giraffes. This research however, demonstrates that GSD may indirectly do so by increasing affected individuals vulnerability to lion predation.

Muneza, A.B., D.W. Linden, M.H. Kimaro, A.J. Dickman, D.W. Macdonald, G.J. Roloff, M.W. Hayward, and R.A. Montgomery. 2022. Exploring the connections between giraffe skin disease and lion predation. Journal of Zoology 316:49-60.