Date: 3/20/26 10:57 am From: Dominik Mosur via groups.io <dominikmosur...> Subject: [SFBirds] Breeding Atlas news and miscellaneous observations from recent days
The California Breeding Bird Atlas held its first virtual Town Hall meet up last night. For anyone who thought about joining the project but was hesitating or wanted more information, this video answers a lot of questions:
Some breeding bird activity from my personal notes:
Band-tailed Pigeons - a pair was observed copulating in a Redwood tree next to the Aldea Housing community building on Johnstone/Mount Sutro OSP. This species is quite secretive in building nests high up in dense trees so I'm calling on folks to put in an effort to locate one for this spring. Band-tails are also regularly seen displaying around the Forest Hill/Inner Sunset Neighborhoods nearby as well so searching some of the small parks could be productive.
White-throated Swifts - multiple birds were noted on March 9th in the vicinity of probable nest sites along the HWY 280 corridor and at the 101 interchange. This species is also notably hard to "nail down" with confirmation codes so anyone who doesn't mind birding near freeway overpasses is encouraged to make periodic visits and see what we can document. The highway overpasses in the presidio are another place to look for swift nests.
California Gulls - the breeding colony on the north facing half of the roof of Recology complex at Pier 96/Cape Henry Berth is ramping up. March 9th 500-600 birds were already present and some engaged in courtship and occasional copulation, outnumbering the Western gulls by about 10 to 1. This spot is quite far for me to bike to so I am encouraging birders on the east side of town to take a look and note any progress like the carrying of nesting material and nest building.
American Crow - five different nest sites in progress at North Lake in Golden Gate Park were noted on March 16th. If you see crows carrying nesting material or building, expand your search of the area and you may find more, as they appear to be loosely colonial to some extent. A week previously, two pairs were working on nests at Gamble Memorial Park in the Haight.
Violet-green Swallows - first arrivals in the airspace between Corona Hill and Buena Vista Park were noted on 2/25 and have been noted daily since. Courtship behavior is increasing now and this species breeds in the area and throughout the city but sites are difficult to locate. Most in my experience have been in roof cavities of buildings rather than in natural cavities; the so called "spanish tile" roofs are especially popular although I've seen ventilation vents with broken/missing screens also being used.
Red-winged Blackbirds (California Bicolored) - the colony at Pier 94 was in full swing with nest building noted March 9th. Red-winged Blackbirds have become quite scarce in SF with continuing loss of habitat, other locations to check: Candlestick Park (especially around the seasonal wetland at the main entrance), Golden Gate Park lakes (Blue Heron, Elk Glen, North Lake et al), Lake Merced.
I've also located two nests of Cooper's Hawks and a potential Barn Owl nest; I can share the location off list with a volunteer or two who are willing to monitor these. I have additional target species assignments for anyone who is interested.
Happy spring birding and get out there and find some nests!
If you have questions please don't hesitate,
Dominik Mosur San Francisco CA Breeding Bird Atlas crew
