USA National Phenology Network - Nature’s Notebook Report
Audubon Bobcat Ranch is a cattle ranch owned by California Audubon Society. It is approximately 7,000 acres much of which is mixed blue oak woodlands and grasslands. Cattle graze parts of it intermittently in order to sustain the habitat.
Blue-Gray Gnatcatcher
Yolo Audubon Society has been conducting phenology surveys here for 7+ years.
Late spring to early summer saw the return of the summer residents ash-throated flycatchers, western kingbirds and Bullock’s orioles. Ash-throated flycatchers increased through May and June likely due to successful fledging. A similar but muted increase occurred with the western kingbirds. Seemingly the Bullock’s orioles were not inclined to stay and breed as they were only found early.
Red-tailed Hawk
In addition to the apparent successful reproduction experienced by the above flycatchers, red-tailed hawks, killdeers, American kestrels, cliff swallows, oak titmice, and white-breasted nuthatches appeared to have successfully reproduced.
We were able to monitor a pair of red-tailed hawks that used a near-by nest to produce two fledglings. We have seen red-tailed hawks with first-year feathering several time throughout the summer. We assume these birds are one or both of those that fledged in early summer.
Ash-throated Flycatcher
The local pair of American kestrels probably produced a single offspring this year. These birds have used a cavity in a dead blue oak for at least two years. Last year two birds were probably fledged from this nest.
As in previous years, we documented several flights of high flying cliff swallows. Although we have not identified the origin to these birds we think they are from a community colony that exists in the basalt cliffs on the western part on the ranch. Probably these flocks are a mix of parents and fledglings that are beginning to migrate.
In the latter part of the summer, we saw north to south, insectivore migrants. Prominent members were blue-gray gnatcatchers, yellow warblers, orange-crowned warblers, Wilson’s warblers, and warbling vireos.
Photos (clockwise from top left): Blue-gray Gnatcatcher (Joshua Greenfield), Immature Red-tailed Hawk (Kelli O’Neill), Ash-throated Flycatcher (William Hemstrom), Fog rolling easterly over Bobcat Ranch (Kelli O’Neill),
–Joe Zinkl, Bobcat Ranch Phenology Study Chair