In many semi-arid savanna ecosystems, surface water is scarce and only found in artificially pumped waterholes at the end of the dry season, leading to high large mammal densities and competition. Further, the modification of the physico-chemical characteristics of the drinking water over the dry season (e.g. through faeces accumulation) could enhance competition. Indeed, elephants, considered as key-competitor, and other herbivores by aggregating near the trough where clear water arrives could compete for this resource. We studied the drinking locations of eight herbivore species around pumped waterholes in relation to these water characteristics in Hwange National Park, Zimbabwe. We identified differences of the physico-chemical characteristics of the water in different sections of pumped waterholes at the end of the dry season. Elephants drank the water in or close to the trough, whereas other species drank further in the waterhole, except roan and sable antelopes which were indifferent about where they drank. Interference competition with elephants for the access to water close to the trough was not detected for zebras and kudus. We discuss possible directions for future research to enhance our understanding of waterhole use by herbivores.

Supplementary Figure S1: Mean annual diet sample mass recovered from macaroni penguins Eudyptes chrysolophus and eastern rockhopper penguins E. filholi (sampled during the chick-rearing period, Dec-Feb or Jan-Mar, respectively) at Marion Island, from 1994 to 2018. (Note: No data were collected for eastern rockhopper penguins in 2002) 100 200 300 400

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