Swishing the tip, or fingers, of the trunk back and forth on the surface of the water to disperse floating debris. Then, placing a partially submerged trunk tip parallel to the surface of the water, slowly and gently sucking in ‘filtered’ water. The filtering process may be repeated for each trunkful. Filter-Water is employed by adults and adolescents, but we are unsure at what age this technique is acquired by younger elephants.
Young males are drinking. The male on the left of the pair takes a trunkful of water and pours it into his mouth. Then he takes a second trunkful - carefully syphoning it from the upper layer of the water. But he seems to get some debris in it and discards the trunkful squirting it out. In the second part of the clip he swishes the water back and forth cleaning the surface before sucking. Both are commonly seen techniques. (Gorongosa, Mozambique)
