Shortly after 11 a.m. on Saturday a large flock of buffleheads, common goldeneye and scaup floating on the southwest side of Sengekontacket Pond began to move as a unit towards the frozen marshes on the shore of the pond. At first there appeared to be no reason for this shift in location. Then, about 10 minutes later, a young bald eagle soared into view high overhead.

“No doubt,” said Brad Winn, a conservation specialist at Manomet Center for Conservation Sciences, aiming his telephoto lens up at the eagle to snap a photo of the predator.

A Guinea Fowl was one of the 16,378 Vineyard birds counted on Saturday. — Lanny McDowell

Mr. Winn was one of many volunteers out on Saturday participating in the Christmas Bird Count, an annual census of birds across the hemisphere now in its 114th year. Counts have taken place on the Vineyard for the past 54 years.

Mr. Winn added the eagle, buffleheads, scaup and goldeneye to a growing list of Island bird species he had been tallying since first light. By sundown he and his teammates — Tom Chase, Linda Deegan, Chris Neill and Dave and Shelley Small — would record 76 unique bird species in Oak Bluffs alone.

Mr. Winn began his career at age 11, following Vineyard naturalist Gus Ben David around and “asking a lot of questions.”

The worldwide bird count took place between Dec. 15 and Jan. 5 with the Vineyard’s count occurring on Jan. 4. It’s the oldest citizen scientist survey in the world and relies entirely on the efforts of volunteers. In addition to the teams out in the fields and forests, volunteers also work the phones, collecting information about bird species spotted at feeders.

Brad Winn participated in four bird counts this season. — Ivy Ashe

Eleven other teams on the Vineyard, working across the Island from Chappy to Gay Head, recorded 118 species in total, and 16,378 individual birds. Work began as early as 4:30 a.m. — prime time for finding owls — and continued until sundown.

When the bird count began 114 years ago, the brainchild of National Audubon Society officer Frank Chapman, it was an outgrowth of the growing conservation movement, and represented a marked shift in how people perceived the world around them. According to the National Audubon Society’s Bird-Lore magazine published in 1900, the count was to be a less macabre twist on a previous tradition of going out on Christmas Day “on the cheerful mission of killing practically everything in fur or feathers that crossed [one’s] path.” The side with the most kills “won” the day.

“Now Bird-Lore proposes a new kind of Christmas side hunt,” the magazine continued.

“They decided let’s just look at them instead of shooting them,” Mr. Winn said.

Twenty seven counts were held that first year, from Massachusetts to Missouri. Last year the United States hosted more than 1,800 counts, with hundreds of tallies also taking place in Canada, Latin America and the Caribbean.    

Two Hooded Mergansers are on the list. — Lanny McDowell

This was the fourth year Mr. Winn participated in the Vineyard bird count. He also did counts this season in Plymouth, Concord and St. Katherine’s Island in Georgia. Each of his teammates also completed multiple counts. Across the nation the count is an exercise in collaboration. Many of the field volunteers on the Vineyard come here specifically to help tally.

Edie Ray made the trip over from Nantucket to join the Aquinnah group. The find of the day up-Island, she said, was a pair of shrikes on Lobsterville Road. “You’re driving along and you think there’s nothing, but then you see something more,” she said.     

Ms. Ray has been doing Christmas bird counts for more than 25 years. Last Sunday she helped out teams on her home island, where the big news was the impressive number of snowy owls spotted (33). On the Vineyard, nine snowy owls were seen during the count, from State Beach to Quansoo.     

Data from last year’s bird count indicated a southward shift in snowy owl territory for the second year in a row.

“A lot of times birds are indicator species,” said volunteer Vasha Brunelle as she worked the phones at Felix Neck, recording sightings of chickadees, cardinals and red-breasted nuthatches at bird feeders. The sheer amount of data National Audubon collects each year on birds and bird species allows for scientists to take note of migration trends across the hemisphere, and to measure the long-term health of populations.

Back at bird count headquarters, David Stanwood, Rob Culbert and Ken Ivory compile the numbers. — Ivy Ashe

“I lived here all my life and it was always ‘A bird’s a bird,’” said Kenny Ivory, who spent the day with a team on the South Shore. Mr. Ivory then took an Adult and Community Education class with bird count compiler Robert Culbert, enjoying it so much he took the class twice more. He started volunteering for the count last year.

“We had some really good birds,” Mr. Culbert said after the final tally was held Saturday night at the Wakeman Center. Mr. Culbert listed several key finds, including the bald eagle: shrikes, a yellow-breasted chat found on Lambert’s Cove Road, several pippets, a short-eared owl, a phoebe.

A “good bird,” Mr. Culbert explained, is simply one that’s not commonly seen on the Vineyard.

“Considering the snow we had, I think [we had] respectable numbers,” Mr. Culbert added. A thick snow cover on the ground on Saturday made for a more challenging count than in previous years, but more species were seen at feeders for a very basic reason: “they’re hungry.”

For Mr. Winn, the bird of the day wasn’t included on the official count. Out on Sengekontacket a tiny white bird poked through the vegetation.

“That’s one of Gus [Ben David’s] pigeons,” Mr. Winn said, snapping a photo. “He will laugh at that.”