Most birds don’t regard humans as threats. Maybe they would if we were still baking four and twenty blackbirds in a pie.

Game birds look at us with suspicion, as they obviously should, but even they know our limits. For instance, mallards are tasty. But they quickly learn that we can’t shoot them in urban parks. They not only run up to us, looking for handouts, they also bring their kids. The truth is: Birds figured us out long before we figured them out.

We could learn a thing or two from Sackville, New Brunswick. Fifty years ago, Sackville had a thriving economy. It was a rail hub. It had a robust manufacturing base. Slowly, these assets disappeared. The town was dying, surrounded by duck-filled wetlands that constricted new development. So local officials made use of what they had and built a boardwalk over the wetland in 1988, creating a waterfowl park. Success was immediate and stunning. Waterfowl congregated along the boardwalk in astonishing numbers.

There is now a reason for tourists to get off the highway and visit Sackville, and they do. I just did.

Sackville’s birds quickly became accustomed to people being confined to the boardwalk. Human presence also discouraged raptors and other predators from coming near. The 55-acre wetland became the safest of safe havens. The birds quickly figured it out, and a variety of ducks began raising families right under the noses of people watching from the boardwalk. Not even dogs discouraged the ducks, since they also were confined to the boardwalk. You could walk a honey badger on a leash, and the ducks wouldn’t even bother to look up.

Think of it as a reverse zoo. The animals roam free, and the people are locked up. Humans fear tigers, but when tigers are confined to a cage, we could sleep outside the bars without a second thought. That’s what the birds do when we’re the ones confined. Humans become a safe part of their daily routine, and they take no notice unless something breaks the routine.

You can see this effect in Maine, too. Bangor’s wetland next to the interstate, Essex Woods, is home to many breeding waterfowl. Birds understand they are safe there, and snooze right next to the walking path. Mallards even collect on the path, often begging for handouts. Passing birds observe all this safety, and drop in for a stay.

Collins Pond in Caribou is renowned. Every autumn, Canada geese visit the nearby fields to forage for leftover grain. Out there, they are fair game for hunters. But as soon as they are nourished, the geese flood into town, flocking to this inner city pond by the thousands. They know they are safe there, and they routinely ignore people on the walking paths next to the pond, despite the fact that humans were mortal enemies just hours before. Other waterfowl and shorebirds see this collection of geese, intuit that it is a safe place, and join the party. Next month, Collins Pond will be a hopping place.

Across North America, some of the best wetlands are actually wastewater treatment plants. In the final stages of purification, treated water is released into ponds, where any remaining organics create great habitat. Waterfowl and wading birds collect in these ponds, and some famous boardwalks have been built over and around them. Here in Maine, the Sanford Sewage Lagoons are awesome. Birds are instinctively aware that no one not going to walk into a sewage lagoon.

You can see this effect with non-ducks, too. Crows on the highway learn that traffic stays in the travel lane, and they are relatively safe in the breakdown lane. Instant death whizzes by just 5 feet away, and they don’t even flinch. Unfortunately, it takes a few mishaps to learn this. There is a period in midsummer when dead crows line the highway. These poor youngsters didn’t discover the safe zone quickly enough.

While I was in Sackville, I spotted a well-concealed nest along the walking path. It was so close you could touch it. Three babies and one adult cedar waxwing stood on the nest, watching me watch them. They were so accustomed to humans walking by that they didn’t even twitch.

Birds get used to people quickly. Relax in a lawn chair next to the bird feeder, and it isn’t long before the birds resume their feeding routines. If we don’t act threateningly, we’re just scenery.

Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. He developed the Maine Birding Trail, with information at mainebirdingtrail.com. He can be reached at duchesne@midmaine.com.