mjm@oliven.olivetti.com (Michael Mammoser) (02/23/89)
On President's Day I went out to Arastradero Preserve, an Open Space Preserve in the western foothills of south San Francisco Bay. It was a pleasant, sunny day and I was interested in whether any breeding activity was taking place (it's not too early in the year for resident species to start courtship activities). Although the Bushtit flocks had not yet broken up into pairs, the Plain Titmice were singing their spring songs. I had heard from a friend that a Great Horned Owl had taken over a Red-Shouldered Hawk nest that had produced hawks last year, but I couldn't find it. However, I did find a pair of Red-Shouldered Hawks on the other side of the preserve. I heard one calling constantly from a eucalyptus grove and, as I walked toward it, scared up the other, which was perched in a tree about 20 ft. away. It flew a short distance and landed in full view, where it stayed for a number of minutes. Also, an adult Cooper's Hawk made a brief appearance in an area where it was suspected of breeding last year. Red-Tailed Hawks and Turkey Vultures were soaring overhead. It was most interesting to watch a pair of courting Black- Shouldered Kites, which breed regularly in the preserve. As one bird sat perched in the top of a tree, the other flew over it in tight circles, dangling its legs, calling continuously, and holding its wings in a very steep dihedral while propelling itself by fluttering its wingtips. It's amazing that 30 or 40 years ago this bird was on the brink of extinction. I was reading in Bent just the other day that there was, in 1932, an estimated 0 to 2 pairs in the whole of Santa Clara County! Now there are probably more pairs than that breeding in the preserve alone. Another interesting bird that I saw was a Phainopepla. A friend had seen two just two days before. These birds are rare in the western hills and are usually breeding across or in the eastern hills. Perhaps we will see them breeding in the preserve this year. One can only hope. The small lake in the preserve had a contingent of Ring-Necked Ducks, Greater Scaup, Lesser scaup, Red-Winged Blackbirds (the bicolored variety), and the ubiquitous Coot. One Tree Swallow was flying overhead (I'd like to find a nesting location for these guys). The day was rounded out with Western Bluebird, Golden-Crowned Sparrow, White-Crowned Sparrow, Western Meadowlark, Chestnut-Backed Chickadee, Bewick's Wren, Hutton's Vireo, Wrentit, California Thrasher, Nutall's Woodpecker, Acorn Woodpecker, Brown Towhee, Rufous-Sided Towhee, Anna's Hummingbird, Black Phoebe, Scrub Jay, White-Breasted Nuthatch, Ruby-Crowned Kinglet, Robin, Song Sparrow, House Finch, Lesser Goldfinch, and Yellow-Rumped Warbler (both Audubon's and Myrtle). Mike