Ken Wiersema talks about swallows when he presents “Acrobats of our Spring and Summer Skies” at the next Olympic Peninsula Audubon Society meeting, set for 7 p.m. Wednesday, March 21, at the Dungeness River Audubon Center, 2151 W. Hendrickson Road.

The program is free and open to the public.

Wiersema is a past president of OPAS, past member of the Audubon Washington State Board, 40-plus-years member of National Audubon and a volunteer instructor at the Dungeness River Audubon Center. He is currently OPAS’s Education Chair.

Wiersema has committed to learning about swallows, building boxes that meet their needs, and collecting photos and sounds of their actions, OPAS members say.