Each year, tens of thousands of volunteers across the Americas join to participate in the Christmas Bird Count (CBC). This event is a census of birds in the western hemisphere that provides population data for science. Yosemite's participation began in 1932; and has since contributed over 100,000 observations to the growing database of bird population trends. For many people, spending the day observing birds, reuniting with birding friends, and contributing to bird conservation makes their holiday season complete. The CBC is the longest-running citizen science survey in Yosemite and in the world.
The most recent Yosemite CBC took place on December 15, 2019, when 43 participants divided up into six groups, with the goal of counting as many species and individual birds as possible. Each group had at least one designated expert leader, who was responsible for the accuracy of the bird identifications and data collection. All day, the groups searched their respective areas, covering a 15-mile radius circle, which included El Portal, Foresta, Yosemite Valley, and Chinquapin/Yosemite West. At the end of the day, everyone convened in Yosemite Valley to eat good food, share birding highlights, and tally results. In 2019, participants tallied 1,781 individual birds comprising 68 species – just below the record high of 70 species.
Keen eyes and ears made for some great birding moments and highlights. The early morning hoots of a great horned owl kicked off the count. Highlights included high numbers of red-shouldered hawk (6) and bald eagle (2) in Yosemite Valley, American kestrel (5), pygmy nuthatch (16), and Lincoln’s sparrow (16) in Foresta, and yellow-rumped warbler (58) throughout the count circle. On the other hand, birders observed low numbers of band-tailed pigeon (4), downy woodpecker (1), western bluebird (26), and California towhee (9). The most surprising species was a red-winged blackbird in Yosemite Valley, which had not been observed in almost 20 years. This species has only been recorded in six different years (1952, 1953, 1976, 1984, 1991, and 2019) since the count began in 1932.
Overall, participants tallied a high number of species, just two species below the record high (68 versus 70 species), however some reliable species such as mallard and lesser goldfinch were missed. Birders in the highest elevation zone recorded the fewest number of species (11) and individual birds (79), while birders in Foresta recorded the highest number of species (44) and individuals (723). American robins (265) boosted the number of birds observed in Foresta, accounting for almost 40% of Foresta’s total. Despite large flocks of robins, the overall number of individual birds observed was the lowest recorded since 2010, in almost a decade.
The next Yosemite Christmas Bird Count is December 20, 2020. To attend the full-day event, bring binoculars, a field guide, lunch, plenty of warm clothes and sturdy shoes. Plan to be outside all day, from around dawn to dusk. An annual compilation potluck dinner closes the day to allow participants to share Yosemite birding highlights. To participate, you must register in advance by contacting the Yosemite Christmas Bird Count Organizer.
Some historic highlights from Yosemite's Christmas Bird Count include:
When bird-watching, experienced birders confidently identify birds by just a glimpse. (See illustrations of Yosemite's most common species.) Remember that a bird’s feathers change as an adult molts into its winter plumage. For many species, a male bird’s winter plumage is dull compared to his colorful plumage in the spring when he is interested in attracting a female with whom to mate. Also, note subtle nuances in a bird’s song or call—long trills or short chips. In the winter, birds rarely sing but make call notes to defend a territory, announce the presence of a predator, or to keep up with a mixed-species foraging flock.
Last updated: March 30, 2020