Diet responses of two apex carnivores (lions and leopards) to wild prey depletion and livestock availability

Prey-depletion is a significant threat facing carnivores globally, resulting in reduced population numbers, diet alterations, and increased livestock consumption, which increases human-carnivore conflict. We compared the diets of lions (Panthera leo) and leopards (P. pardus) in the prey-abundant Kruger National Park (KNP, South Africa), with that in the prey-depleted/livestock-abundant Limpopo National Park (LNP, Mozambique), using scat analyses. Lions and leopards had broader dietary niche breadths and consumed a greater proportion of smaller (previously suboptimal) prey in LNP relative to KNP. Downshifting in lion and leopard prey size consumption and the continued reliance on previously suboptimal prey may adversely affect carnivore fitness. Diet overlap between lions and leopards was low in both KNP and LNP, suggesting that even when prey is depleted, lions and leopards can partition food resources. Whilst consuming livestock in LNP, lions and leopards strongly avoided cattle (Bos taurus), even though they are the most abundant ungulate in LNP. This suggests that lions and leopards modulate their foraging behavior, so reducing human-carnivore conflict. Efforts to promote carnivore recovery and reduce human-carnivore conflict should focus on prey population restoration, particularly large prey. •Lions and leopards down-shifted prey size selection in prey-depleted system.•Lions and leopards avoided cattle.•Diet breadths were broader in prey-depleted vs prey-abundant system.•Low interspecific diet overlap in both prey-abundant and prey-depleted system.