Water-hose tool use and showering behavior by Asian elephants.

Abstract

Since Jane Goodall's famous observations of stick tool use by chimpanzees,¹ animal tool use has been observed in numerous species, including many primates, dolphins, and birds. Some animals, such as New Caledonian crows, even craft tools.^2,3 Elephants frequently use tools^4,5 and also modify them.⁶ We studied water-hose tool use in Asian zoo elephants. Flexibility, extension, and water flow make hoses exceptionally complex tools. Individual elephants differed markedly in their water-hose handling. Female elephant Mary displayed sophisticated hose-showering behaviors. She showed lateralized hose handling, systematically showered her body, and coordinated the trunk-held water hose with limb behaviors. Mary usually grasped the hose behind the tip, using it as a stiff shower head. To reach her back, however, she grasped the hose further from the tip and swung it on her back, using hose flexibility and ballistics. Aggressive interactions between Mary and the younger female elephant, Anchali, ensued around Mary's showering time. At some point, Anchali started pulling the water hose toward herself, lifting and kinking it, then regrasping and compressing the kink. This kink-and-clamp behavior disrupted water flow and was repeated in several sessions as a strict sequence of maneuvers. The efficacy of water flow disruption increased over time. In control experiments with multiple hoses, it was not clear whether Anchali specifically targeted Mary's showering hose. We also observed Anchali pressing down on the water hose, performing an on-hose trunk stand, which also disrupted water flow. We conclude that elephants show sophisticated hose tool use and manipulation. VIDEO ABSTRACT.