George Heleker’s passion for birds started with an aching back.

More than a decade ago, when he was sidelined with a back injury that physical therapy couldn’t seem to help, and getting more out of shape, someone recommended he try walking. That led to outings on trails that included one off the parking lot known as the Clayton Beach day use area. There, he’d set out with a light-weight aluminum chair on a slow walk up a hill. When his back grew sore, he sat down.

Back then, the Bellingham resident could identify just a handful of the birds that came to the feeder in his yard, and robins were the only birds he knew by ear.

Then he heard birds singing during his walks and thought learning about them would be fun. He started walking with binoculars, the better to see the birds with. He brought a field guide, the better to identify them by name. He brought index cards, the better to keep records, including where he was when he saw and heard a particular bird. Year-in, year-out, early in the morning when the birds would be singing, he walked, he waited, and he recorded.

Now, he has nearly 12 years’ worth of records that span from spring to fall. “It wasn’t really my intention but that’s how it worked

out. If you bird in the woods a lot, it’s good to know the sounds because of lot of them, you can’t see,” the 57-year-old Heleker says. “I guess I’m basically a curious person. I found that I love bird songs. It was fun finding out what song was attached to what bird.” His favorite outings – and busiest time for birding – are from spring to mid-summer, when birds are singing the most.

Now, Heleker helps lead bird outings through North Cascades Audubon Society. One on May 18 and one on May 31 will take participants birding at Lake Padden and the Chuckanuts, with an emphasis on identifying birds by their calls and songs. (Sorry, these outings on “Spring Songbirds” and “Chuckanut Songbirds” are filled.)

Heleker doesn’t know exactly how many birds he can pick out by ear, only that he knows all of the area’s birds.

“I’m sure it’s well over a hundred but I have no idea,” he says. “At this point, I’m probably better by ear than by sight.” His was no easy feat.

Consider that birds have songs and calls. Songs are used to claim territory or to attract mates. Calls could be used for many different reasons. Some birds have a small number of songs and a small number of calls. Others have a vast array.

In addition, Heleker says a few birds have their songs imprinted in their genetics while many more learn them, so the former are easier to learn because the sound is more consistent.

If you’re looking for an easy song, then listen for the olivesided flycatcher because its song is consistent. When Heleker does it, it sounds something like do-DEE-do. A good mnemonic device for remembering it, he says, is to think “quick THREE beers.”

I listened to this Washington bird’s song on the Seattle Audubon Society’s Web site at Birdweb.org, and found that it did sound like “quick THREE beers.”

But Heleker didn’t learn that way, saying he rarely listened to recorded bird sounds.

Instead, he’d search for the bird making a particular sound. Then connect the call or the song to the bird. Doing so isn’t always easy.

Take the Townsend’s warbler and the black-throated warbler. The Townsend’s has an “excruciatingly larger number of different ways” to let the world know it’s a Townsend’s warbler, Heleker says. On top of that, the two warblers’ songs are similar.

Heleker says it took him more than one spring to differentiate between the two. But he didn’t mind the effort, and it’s not only because his back is better.

“I love music and birds are really good at making music,” Heleker says. “It’s not just about the birds, it’s about being out. I feel a connection to nature. It’s relaxing and exhilarating.