Despite the forecast for wet and wild weather this past Saturday, over 80 volunteers throughout San Mateo County's Peninsula spent the day on a mission to count as many birds as they could in a 24-hour period.
The occasion? National Audubon Society's Christmas Bird Count, an annual event that takes place across the United States from Dec. 14 to Jan. 5. Canada and several other countries in the Western Hemisphere also participate each year, according to the Society.
2010 marks the 111th year since ornithologist Frank Chapman came up with an idea in 1900 to count birds during the holidays instead of hunt them.
"The purpose is to collect data which can be used to assess the health of the local bird population over time," said Leslie Flint, San Mateo resident and 10-year veteran of the San Mateo County Peninsula's Christmas Bird Count. This year, Flint served as the area's co-organizer on the Peninsula's Bay side, along with Half Moon Bay residents Jennifer Rycenga and Gary Deghi, who took care of the Coastside.
"It's 'citizen science,'" Flint said, referring to the Christmas Bird Count's practice of using non-scientists to collect data studied by ornithologists and other scientists.
"National Audubon Society (NAS) compiles the data from each of the counts for their database, which helps them decide what sort of conservation areas to focus on," Flint said. "Ornithologists can also use the data to see if there are trends," she added, "by comparing data collected throughout the years."
The database is also available to the public on the NAS website.
"Counting circles," as each unit is called, are comprised of geographical regions that are 15 miles in diameter. Each counting circle is divided up into several areas for small groups to tackle on their own throughout the day. Volunteers note every species they find in their assigned area, and are required to fill out worksheets as detailed as "how far the group drove and how far the group walked," according to Flint.
The San Mateo Peninsula, otherwise known as the Crystal Springs counting circle for the purposes of the Christmas Bird Count, covers the area between Foster City and Half Moon Bay along the east-west axis, and San Bruno Avenue to Huddard Park (on Kings Mountain Road) in Woodside along the north-south axis.
While some head out to spectacular vistas along at the edge of the Pacific Ocean or on the west side of San Francisco Bay, others can choose to tally next to something as ordinary -- though no less interesting, some might say -- as a bird feeder on his or her own front porch.
Though the bird-counting window is technically a 24-hour period, Flint spent about half of Saturday counting, waking up around 5:30 a.m. and finishing her day around 4 p.m. when it got dark.
"The people looking for owls are the ones who count in the dark," she said. "Good places to find owls in the county are along Skyline Blvd., and the Pulgas Ridge Open Space Preserve," she said. "Wavecrest Field in Half Moon Bay is good for finding barn owls because it's a good place for them to hunt," she added.
Many of those who spent the day counting are members of the Audubon Society's Sequoia Chapter, which encompasses San Mateo County. While Flint and Rycenga worked as co-organizers, recruiting and assigning volunteers to small teams throughout the 19 defined areas within the counting circle, volunteer Al DeMartini from San Mateo was a "compiler" -- the person who summed up the total number of species found throughout the day based on reports sent to him by each team.
On Sunday, DeMartini announced in an email to the Peninsula Birding Yahoo group that a total number of 190 species were counted during Saturday's Crystal Springs event -- a preliminary result, he noted, as he had not received all the reports to date.
DeMartini's written highlights of the day were mainly concentrated in Half Moon Bay, among them the sighting of two Swainson's Hawks in the Wavecrest area and three Pacific Golden Plovers at the . However, he also noted two Vaux's Swifts flying over San Carlos, Clapper Rails in Millbrae, a Palm Warbler in Redwood Shores ("between the library and the levee"), and a Pileated Woodpecker at the Filoli Estate in Woodside.
According to DeMartini, the Crystal Springs counting circle also found Marbled & Ancient Murrelets, Rhino Auks, "flyover" White Pelicans, Golden Eagles, two Ospreys, and a Bald Eagle, among several other bird species.
"And possibly more that I forgot!" DeMartini's email exclaimed.
Half Moon Bay resident, biologist and birding guide Alvaro Jaramillo said that he first saw the Swainson's Hawks in town on November 26, and that their winter appearance in Half Moon Bay was unusual. "Swainson's Hawks breed in North America but they spend the winter largely in Argentina and Uruguay," he said, noting that he had recently returned from Uruguay, where he saw "hundreds" of them.
"Recently a subset of the species has started to winter in California, largely in the Central Valley," Jaramillo said, "and now Half Moon Bay." Though he said it was unclear as to why it was happening, "we may be witnessing a change in wintering distribution right before our eyes," he said.
"If these birds do well here they may come back in other years, and maybe their offspring will too," Jaramillo said.
Flint also described two trends observed from the Peninsula Christmas Bird Count data.
"Ten years ago someone challenged me to see a crow in Foster City," she said, noting that crows are "town" birds that crop up around developed areas. "Crows eat garbage, dead animals on the street," Flint said. "You'll find them anywhere you have more human habitation," she said.
That year, she saw one crow.
"On Saturday, I saw 250 crows," she said, noting that the crow count was likely to be a reflection of Foster City's development.
Flint also said that local data has hinted at one example of a species that could be crowding out another within the county. She cited data from over the last few years showing that while the total count of Eurasian Collared Doves has been rising in the Crystal Springs counting circle, the total count of Morning Doves has been decreasing in the same area.
Flint also said that Rycenga told her that on Saturday during the count in Half Moon Bay, she [Rycenga] saw ten times more Eurasian Collared Doves than Morning Doves.
"We know that Eurasian Collared Doves compete with Morning Doves," Flint said.
DeMartini and Flint both expressed that Saturday's total thus far would place the San Mateo Peninsula among the top areas in the country for the highest number of different species sighted in one day.
The Texas Coast usually has the top count in the U.S., Flint said, but other Bay Area counts in Pt. Reyes and Oakland also regularly rank among the top 20 in the nation.
"It's not a competition or anything," Flint said. "But the advantage of the Peninsula is that we have bayside and coast and the mountains in between – tremendous diversity of habitat," she said.