Castle Rock/Diablo Foothills Regional Park, Walnut Creek
Migrant activity is beginning to tick up nicely as my outing to Diablo Foothills, this morning, was to reveal.
Walking through the Castle Rock recreation area ( where I began a little after 7am), I noticed that there
are still a fair number of Golden-crowned Sparrows. A considerably smaller number of White-crowned
Sparrows were distributed around the general area. Small numbers of California Quail foraged over
the little ball field. Several House Finches carried nesting materials in the pic-nic areas near the
pool. All of the Western Bluebirds I saw wore their vibrant dark azure, characteristic of Spring.
Further up the road, about 150 feet beyond the ball field, I spotted my FOS Bullock's Oriole. The richness
of deep orange plumage on this male can not be overstated. In the next couple of weeks we should
be able to find at least five nesting pair from the pool area up to, and beyond where I found this morning's
bird. Nearby, there was a single Pine Siskin.
Moving on, I heard, and then spotted, a brightly singing Rufous-crowned Sparrow. It was about 100 feet beyond
the first cattle gate. Orange-crowned Warblers were also heard. I would continue to hear, and see, several more
throughout the morning. Most of the Yellow-rumped Warblers have molted into their alternate finery. One among the
several I saw was a very bright and distinct Myrtle.
I then made my way to the Castle Rocks, and while it took a few minutes, saw one of the Peregrines. Along the way to the
State Park boundary, at the second cattle gate, I had my FOS Wilson's Warbler, Warbling Vireo, Hutton's Vireo,
and Cassin's Vireo. Upon my return, there were numerous White-throated Swifts, and a few Violet-green Swallows well
above the Castle Rocks. Soaring higher still, was a single Golden Eagle.
Good birding, all.