Nathan Pieplow, author of the “Peterson Field Guide to Bird Sounds,” will deliver a free, illustrated lecture on The Language of Birds, 7 p.m. Wednesday, Sept. 17 in Fleischmann Auditorium at the Santa Barbara Museum of Natural History.

The free event is presented by the Santa Barbara Audubon Society and Santa Barbara Museum of Natural History and is open to the public.

“All around us, the birds are constantly telling us who they are and what they are doing,” the Audubon Society said. “In this fascinating illustrated talk, Nathan Pieplow unlocks the secrets of their language.

“We’ll listen in on the pillow talk of a pair of red-winged blackbirds, and learn the secret signals that cliff swallows use when they have found food. We’ll learn how one bird sound can have many meanings, and how one meaning can have many sounds — and how, sometimes, the meaning isn’t in the sounds at all.”

Pieplow’s “Peterson Field Guide to Bird Sounds,” is published in two volumes, one for Eastern and one for Western North America.

An avid bird sound recordist and videographer, Pieplow is the author of the bird sound blog Earbirding.com, a board member of the Bird Conservancy of the Rockies, an author of the Colorado Birding Trail, and former editor of the journal Colorado Birds.

He teaches writing and rhetoric at the University of Colorado in Boulder.

For more, call the Santa Barbara Audubon Society, 805-964-1468.