On the northern coast of Peru, men are measured not by their car or their clothes or their career, but by the strength of their whistle.

Knowing this, boys make pincers of their hands, tuck them into the corners of their mouths and blow until their eyes bulge. Usually they can emit no more than a disappointing “ffft,” like air sneaking from a tire. But they persist until one day, out comes a whistle so shrill it rings their ears. They keep blowing until the entire block knows that another man has been born.

They soon realize that the most important whistle is one they knew all along: the wolf-whistle. They’d heard men use it — that sharp rise in pitch followed by a fading descent — but until puberty, they didn’t know why.

It’s a game of courtship played throughout Latin America, but perhaps nowhere with more regularity than on the streets of Piura, Trujillo and other cities on Peru’s northern coast. It’s a game so predictable that it feels scripted, as if the men and women are actors in a lazy street troupe.

I was heading down the coast by bus from Ecuador to southern Peru, along northern Peru’s so-called Gringo Trail. Nowadays it’s more like an international highway, full of tourists with luggage and printed itineraries, not hippies with backpacks and mangled guidebooks.

It was in Piura where I had the privilege of experiencing something usually reserved for women: Locals of the opposite sex frequently whistled at me. Flattered rather than offended — they were almost always young, attractive women — I would smile back and they would giggle. And that would be that.

One evening when I was attending a soccer tournament, thousands of men in my section erupted into a cacophony of wolf-whistling. This usually indicated the crowd’s objection to a call on the field. But the Peruvian crowd was showing little interest in the match, which featured the Mexican and Ecuadorian national teams.

Instead, the object of the crowd’s attention was a young blond-haired woman walking between the first row and the field. From men in suits to men in soiled T-shirts, they were all watching on her. To her credit, she didn’t falter, but she blushed, dropped her head and smiled like someone who had just tripped on the street.

I felt no temptation to wolf-whistle — then or ever. But encouraged by one too many swigs of rum, I stood up, turned to the crowd and raised my hands. “Amigos, amigos, por favor,” I pleaded with a smirk, as if nudging them collectively in the side and winking. The crowd erupted into laughter. Whistlers or not — Peruvian or not — men are men.

Nothing on the northern coast compares to southern sites like Machu Picchu, the magical ruins of the famous Incan city, or Colca Canyon, the deepest canyon on Earth. But Trujillo, the northern coast’s largest and most attractive city, is worth a visit.

I liked the place for its bright colonial architecture, spring-like climate, and its history. Trujillo is home to pre-Columbian sites like the pre-Inca Chim?? capital Chan Chan, one of the largest adobe cities in the world, and to temples attributed to the still-earlier Moche culture. Huanchaco, a nearby beach town, is popular with sunbathers and surfers. And the seafood is fantastic. Perhaps the best ceviche in the world is served here.

As in Piura, though, I was most attracted to the people. The Trujillo women were strikingly beautiful. A recent Miss USA was Trujillo native. This, of course, only goads on the whistlers. Sometimes it’s no more than a sign of friendliness.

Trujillians, as well as folks in Piura and the “capital of friendship,” Chiclayo, are more amiable than southern Peruvians, who are accustomed to (and perhaps tired of) tourists.

Every weekday after lunch, Trujillo shuts down for a three-hour siesta. Businesses, even the chain supermarkets, lock their doors between 1 p.m. and 4 p.m., and the swarms of cabs dissipate. Men of all ages and classes step outside and stand in groups, idly talking.

Inevitably, an attractive woman approaches. She may be alone or with a friend, or even with her parents or boyfriend. Or she could be a tourist. It makes no difference: The men will turn and stare at her shamelessly and then break into whistles.

The woman always keeps walking, eyes straight ahead, as though she hasn’t heard a thing. The men, smiling, turn back toward one another after she passes. They discuss the merits of her body and suggest what they would do if, someday, they happen to find themselves in bed with her.

Peruvian women tell me they hate being whistled at, but then add, “It’s a macho culture,” as if to say, “That’s just the way it is.” Foreign women tend to be less forgiving. I wouldn?t be surprised if the blond woman at the stadium later asked a friend, “Do they really think they?re going to pick up a woman that way?”

But that’s missing the point. The wolf-whistle seems less a mating call than a shallow display of masculinity, like grabbing your crotch or spitting. The whistles, I mean, are not really meant for the women. They are for the men.