On 6 February 1971 we were observing waterfowl in the Dune Lakes region 20 miles southwest of San Luis Obispo, California. A group of Mallards Anas platyrhynchos was resting in some willows Salix lasiolepis growing on the banks of one of the lakes (this lake of approximately 55 acres was also surrounded by tules Scirpus acutus). Another group of Mallards was swimming, courting, and bathing in the water near the edge of the lake. After bathing, four males and two females ascended some of the willow branches projecting over the water.