2021 SF Christmas Bird Count Report
By David Assmann
San Francisco birders have been lucky – for the past fifteen years, there has been no rain on the Christmas Bird Count, and conditions have been mostly sunny, with a rare bit of fog. The December 28, 2021 count, however, was cold and cloudy, with light rain at various points throughout the day.
The weather, while reducing visibility and bird activity, did not deter 136 enthusiastic volunteers from making this one of the better Christmas Bird Counts. Participants ended up tallying more than 64,000 birds by the time the count ended – down only slightly from last year’s total on a sunny day, and well above our 10 year average.

We completed our transition to modernizing the count by reporting and compiling all data through eBird, including the documentation for rare birds. eBird’s new Trip Report feature made it much easier to consolidate information and share it with area leaders. 273 eBird checklists were submitted, an increase over last year.
By the time Count Week was over, the species tally was at least 187, and may reach 188 if the Mexican Duck, the rarest bird spotted on the count, is accepted. Illustrating the trickiness of bird identification, there is disagreement about whether or not this bird is a pure Mexican Duck, or if it also has Mallard genes. This determination will likely be made by the California Records Bird Committee, since this sighting is going to be submitted for review.

There were 28 rare species found, with nine of the eighteen areas finding a rare species. Six of the rare species were found during Count Week, but not on Count Day. New to the San Francisco Count were the Mexican Duck in Colma, and a White-winged Dove found during Count Week on Washington Street in a backyard. A Prairie Warbler found near Colma Creek in South San Francisco marked the first sighting of this species during the count since 1993.
Overall duck numbers were similar to prior years, but there was a lot of variation by species. There were only two Green-winged Teal spotted, down from 58 last year, and we missed Cinnamon Teal and Eurasian Wigeon altogether. Scaup numbers, however, were up from last year’s 611 to 1,069 this year (still well below historical numbers). We did set two count records for duck species, with eight Common Mergansers and 62 Red-breasted Mergansers.…