Birders across the South Sound will be heading out starting this week to take part in the 113th Christmas Bird Count.

The event, running from Friday through Jan. 5, involves more than 63,000 volunteers across North and Latin America counting how many birds and species they see. The data, gathered during more than 2,200 counts, are used to provide an assessment of bird populations.

While participants dutifully count common species such as robins and Canada geese, they do occasionally come across a rare bird.

That was the case in 2011, when the Tacoma count had a Eurasian collared dove on its list for the first time, said Faye McAdams Hands, who coordinates the count for the Tahoma Audubon Society.

“This is a Eurasian bird that was introduced to the Bahamas in the 1970s, and then self-introduced from Florida, and has since made its way across the United States, arriving first in Washington about three to four years ago,” McAdams Hands said.

“Another immigrant of note, we also had a high count of 108 Anna’s Hummingbirds, which are now apparently here to stay, to the delight of many birders and bird-feeders,” she said.

That hummingbird species has increased its range from farther south, showing up initially in the Tacoma count with just two birds in the late 1990s. Last year’s count was the highest.

In hopes of attracting more partipants, the Audubon Society has decided to make the count free. In the past, there was a $5 fee per participant, McAdams Hand said.

There are counts conducted at more than 50 locations across Washington, including a number in the South Sound. Here are the details of local counts:

Tacoma: Dec. 15. The Tahoma Audubon Society holds counts at eight locations across Pierce County. Here is the contact information for each area:

Area 1: North Tacoma, including Point Defiance Park, Ruston, Proctor District south to Sixth Street; Art Wang, 253-752-1714.

Area 2: Northeast Tacoma and Brown’s Point to Dash Point State Park, and the Port of Tacoma area to the Puyallup River, Faye McAdams Hands, 253-942-9233.

Area 3: Gig Harbor area; Diane Yorgason-Quinn, 253-857-3367.

Area 4: Hillsdale, Parkland and Joint Base Lewis-McChord, Roxy and Bill Giddings, 253-537-3075.

Area 5: Fircrest, University Place and Lakewood; Rolan Nelson, 253-330-9545.

Area 6: Steilacoom and American Lake; Marcus Roening, 253-756-0215.

Area 7: Fife area; Shelley Parker, 253-862-9350.

Area 8: Day Island, Titlow Beach and Tacoma north of Fircrest through downtown to the Puyallup River; Ruth Sullivan, 253-564-7419.

Information: tahomaaudubon.org

Olympia: The Black Hills Audubon Society will hold its count Dec. 16. The count concludes with the traditional chili feed shortly after dark at Temple Beth Hatfiloh at Eighth and Washington in Olympia. If you would like to participate, contact Bill Shelmerdine at cbc@blackhills-audubon. org or 360-866-9106. Information: blackhills audubon.org.

Kitsap County: To get more details, contact Gene Bullock at 360-394-5635 or genebullock@comcast.net. Information: kitsapaudubon.org

Vashon Island: The Vashon Island Audubon Society will count Dec. 30. To participate, contact Sue Trevathan at sue.trevathan@ centurytel.net or 206-463-1484. Information: vashonaudubon.org

Kent-Auburn: The Rainier Audubon Society will hold its count Dec. 30. To take part, contact Nancy Streiffert at nancy streifert@hotmail.com or 253-796-2203 Information: rainieraudubon.org

Seattle: The Seattle Audubon Society’s count will be Dec. 29, but people are asked to register by Dec. 17. Information: seattleaudubon.org

Long Beach: The Leadbetter Count Circle will take place Saturday on the Long Beach Peninsula. To take part, contact Suzy Whittey at cwhittey@pacifier.com or 360-642-2239.