Date: 9/24/17 7:12 am From: Dominik Mosur <polskatata...> [SFBirds] <SFBirds-noreply...> Subject: [SFBirds] Possible Black-chinned Hummingbird @ Sunset Reservoir 9/23/17
Yesterday afternoon following the Round Up I headed over to my neighborhood Hawkwatch perch, the north side of Sunset Reservoir.
In the Tea Tree grove just below the junction of Pacheco and 28th Avenue there was an interesting hummingbird that made some brief appearances perching in the open before being driven into cover by aggressive male Anna's. It appeared at times to fly across the street to a blooming strawberry tree next to 1967 28th Avenue.
A combination of field marks lead me to suspect it may be an immature Black-chinned hummingbird. The bird had a very clean/pale look to the underparts with a pale buff wash to the flanks, a clean pale gray throat with just a few darker central feathers. A pale gray supercilium terminating with a white spot behind the eye gave it a gray crowned appearance. The bill was petite/thin black and slightly decurved. The overall build of the bird was more slim/smaller than
Anna's. What first got my attention about this hummingbird was the soft "tsip" calls it made, in contrast to the staccato "chup" of the Anna's hummingbird(s) that would drive it off its perch and away from the strawberry tree.
A few photos were obtained using phone camera through scope and can be seen in the eBird checklist here: