Date: 6/17/25 2:30 pm From: Dominik Mosur via groups.io <dominikmosur...> Subject: [SFBirds] First SF record of breeding Blue-gray Gnatcatcher + other breeding/misc. observations
Hello SFBirders,
Starting with the big news. On June 12th, Margarita Montenegro, field biologist for the Presidio Trust discovered a still-begging fledgling Blue-gray Gnatcatcher in the company of an adult in the Tennessee Hollow area of the Presidio ( YMCA Reach just north of the jct of Presidio Blvd. and MacArthur,) This establishes the first breeding record for the species in San Francisco County. It may also be the most coastal breeding record of Gnatcatcher north of Monterey County. (If anyone is aware of any coastal breeding records from San Mateo Co. north please let me know.)
Blue-gray Gnatcatchers were present in the area all spring but this was not a species I expected to ever nest in the City. Their preferred habitat in the West is typically a mix of dry oak woodland and chaparral away from the coastal fog belt.
In other news, on 6/15, during Mount Sutro point counts I confirmed breeding Olive-sided Flycatcher. Both adults were frequenting the upper reach of Woodland Canyon at the junction of the Edgewood and Historic trails and after some waiting around I observed one of them fly into a nest with a large insect and carry away a fecal sac. Olive-sided Flycatchers were present in this same location last summer but I was not able to confirm nesting. In 2023 they nested in almost the exact spot, using a tree that is about 10 meters away from this year's nest tree. Both times they have used a Monterey Cypress. To my knowledge this is the only breeding Olive-sided flycatcher location in San Francisco for almost a decade since they last nested on Mount Davidson c 2016-17.
Multiple recently fledged Wilson's Warblers were also present along the Sutro trails.
The California Gull breeding colony on the Southeast Bayside is also going strong again this year. Over 1100+ were present yesterday with dozens of juveniles of various sizes, outnumbering the western gulls by about 4:1. This site can be observed from the Pier 96 parking lot; the nests are on the north facing side of the Recology building.
While spring migration has pretty much ended a few birds are still moving through. This morning in Glen Canyon, (6/17) there was another ROSE-BREASTED GROSBEAK (10th ? one noted in SF this spring) as well as a getting late singing Western Tanager.
Yesterday (6/16) I noted the first returning Willet in alternate plumage at Heron's Head Park and another observer noted (5)together at Crissy Field.. This is a somewhat typical first return date. Per Ron Thorn's notes the earliest arrival date is 6/9.
On 6/10 the first dispersing hatch-year Orange-crowned Warbler was on Corona Hill and on 6/14 a couple dozen tardy Cedar Waxwings passed through.
