The Olympic Peninsula Audubon Society is marking the 40th anniversary of its national charter this month with a party and finger-food buffet on Sept. 18 that’s free and open to the public.

Dennis Paulson, a nationally renowned author on aquatic birds, presents “Birds of the Wind: The Lives of Shorebirds” and OPAS member Ken Wiersma will give a slide presentation on the society’s four-decade history. RSVP to www.brownpapertickets.com/event/436887.

Festivities begin at 5 p.m. in the Red Cedar Room on the Jamestown S’Klallam Tribe’s campus in Blyn.

The first Audubon Society began in Massachusetts in 1896, named for John J. Audubon, a prolific American painter of birds. The group sought to conserve habitat for declining populations of birds like the snowy egret, which were killed by the thousands to decorate women’s hats. The national organization was established in 1905 and the first chapter in Washington began in the 1920s in Seattle. One of its board members, Hazel Wolf, was instrumental in starting the Sequim chapter in 1972, as well as 21 of the state’s 26 current chapters from the 1960s forward.

“Our first president was Gunnar Fagerlund and there were about 25-30 original members,” said Ken Wiersma, the group’s historian. “Through the years we’ve grown from being a bird identification and education group to also one for advocacy, policy and conservation of bird habitat. Now we have 300 local members and another 150 who live here but are members of the national organization.”

The nonprofit Sequim chapter covers all of Clallam County and dues are $20 per year.

“The neat thing about our chapter is our Christmas Bird Count because of the unique habitats here: saltwater, freshwater, dry plains, prairie, uplands, highlands and mountains,” Wiersma said.

“We have a marvelous array of bird habitat. Over the past 15 years of the Christmas Bird Count, our chapter can count more species than anywhere in the state — between 140-150 different birds in one day — it goes to the breadth of our habitat with lakes, rivers, ponds and a lot of migratory birds from the north that overwinter here.”

Wiersma said the Sequim chapter’s territory is officially an IBA — Important Bird Area — one of about 50 in Washington.

One of the greatest achievements of the group is the Dungeness River Audubon Center in Railroad Bridge Park, built in 2000-2001, with its partners, the Jamestown S’Klallam Tribe and Audubon Washington.

“The chapter engaged in putting the center together since the 1990s; the park is tribal trust land and the Dungeness River Audubon Center is the operating agent for the park,” Wiersma said.

The site is a repository for a large collection of taxidermic birds and a few area animals and serves both indoors and outdoors as an educational center. Members present classes open to the public and OPAS maintains a close relationship with the area’s school children, supporting field trips, speakers and the Dungeness River Festival. OPAS also gives scholarships to current high school students to do research projects on birds and their habitats. Come rain or shine, the center offers bird walks in Railroad Bridge Park every Wednesday at 8:30 a.m. and has for more than a decade.

The first week of April, OPAS hosts BirdFest with bird counts, a dinner, silent auction and prominent speaker, Owl Prowl and a birding cruise to the San Juan Islands. Attracting now about 200 aviary aficionados among the events, proceeds support the center’s educational programs. Just recently, OPAS gave the center a large flatscreen high-definition TV and projection system for educational programs, a gift valued at $3,500-$4,000. The chapter, with Kiwanis and others, also funded an impressive viewing platform at Dungeness Landing.

For more information on OPAS, see www.olympicpeninsulaaudubon.org.