A.Dixon 1950 Falco sparverius Feb 3. NE slope San Pablo Ridge, Contra Costa Co., Calif. Cloudy, cold day; wind from E 16 mph. Gulch II of gravel study area. At 10:30 AM I entered gulch from N and saw an immature Cooper Hawk (large for A. striatus) perched atop a Phleomnus on lower part of ridge between 1st & 2nd side draws. A Sparrow Hawk which inhabits this upper part of the gulch regularly flew low over the perched hawk giving its shrill kelee kelee kelee kelee kelee . The Falco then returned toward the westward again making a pass at the Cooper Hawk. A third pass was silent as the second had been. After the fourth pass (how many before I entered draw?) the Sparrow Hawk ceased and the Accipiter flew down canyon. Back brownish; much white near rump. Sept. 10. +1 mi. N Clayton, Contra Costa Co., Calif. see Journal p. 43-44 for brief account of taking of a sparrow in a grainfield by a Sparrow Hawk.