Field Notes Doug Bell April 24, 1988 From 14:00 - 17:30 hours Maren and I hiked up and down Pine Canyon, off of Castle Rock Park, at the foot of Mt. Diablo (west side), Contra Costa County, Calif. The weather was cool, intermittent cloudy/sunny. Lots of wildflowers, many meadows were still green. The more exposed hills of Mt. Diablo are brown and dried. We saw several male and 2 female Mallards at the dam & sulphur springs. Lots of Redwings along creek. Many Calif. Quail calling. A pair of Red-tails and usually 5-8 Turkey Vultures soaring about the rocks. 2 Kestrels near the first batch of rocks. Heard a Steller's jay imitate the "chuck e-chuck" call of a falcon! Saw one Prairie Falcon, high over the rocky ridges, flying in a slow, straight line due north. It looked to be molting. No other falcons seen. The old stick nest-which I saw here over in 1974 in the largest rock, is still present - looks freshly renovated. Lots of cliff Swallows in various overhangs. A good potential falcon pothole was seen on a ridge-top, SE facing rock south of the main cliff. Lots of operement: Kestrel, Prairie Falcon? But, lots of people in this area. Some rock climbers too. Other birds: Robin, Junco (nesting), House Wrens around along the creek - nesting. Northern Orioles, Black-headed Grosbeaks, White-throated Swifts, Warbling Vireo (2), Brown Towhee, Rufous-sided Towhee, Bushtit, Nuttall's Woodpecker, Flieser, Crow Jay, Starling, Bewans Blackbird