South on ‘Hummingbird Hwy.’

Every year they come in droves to southeastern Arizona on the trail of the world’s smallest bird, what John James Audubon called a “glittering fragment of the rainbow.”

During the late-summer hummingbird season, thousands of tourists from around the world can be seen jockeying for position at the birds’ well-known pit stops on the upper part of the “hummingbird highway”--the verdant corridor of land along the San Pedro River.

As testament to their devotion, tourists have spawned a cottage industry of bed-and-breakfasts and backyard hummingbird-feeder tours, dumping around $10 million annually into southeastern Arizona’s economy. Until recently, there was only one place they wouldn’t follow the tiny objects of their desire.

“For whatever reason--fear, the language difference, whatever--birding stopped at the border,” said Tom Wood, director of the Southeastern Arizona Bird Observatory.

Wood’s group is working to change that by sponsoring a bus tour along with the city of Naco, Mexico, to take birders to hummingbird gardens in two San Pedro basin communal farms in northern Mexico.

Environmentalists are hoping the tour will manage a delicate balancing act--stimulating northern Mexico’s economy, while inspiring area cattle ranchers to conserve parts of their land as American-style bird sanctuaries.

The key to the project’s success, proponents say, is convincing these ranchers that fencing parts of their land along the San Pedro from cattle will attract not only hummingbirds, but tourists.

As Wood puts it, “We’re trying to help the people down there make a living from the land in as gentle a way as possible.”

Despite the good intentions, some see it as meddling.

Sue Chilton, a member of the Arizona Game and Fish Commission who married into a southern Arizona ranching family, said cattle and hummingbirds have been coexisting successfully in the region for 300 years.

“You can’t just announce that we American tourists want to see a cattle-free system, so get lost,” she said. “I think it’s very important not to come across like, ‘Please move your place of business, your sustenance, your livelihood, your 300 years of culture, so we can recreate there.’ ”

Chilton’s husband, Jim, a fifth-generation Arizona rancher, said: “The cattle and the birds coexist on my ranch quite wonderfully. We have riparian environment on our private land and we have cattle, and the assumption that you have to fence off cattle to sustain birds is false, period.”

Officials of the bird observatory, however, say that cattle are a detriment to hummingbird habitats and that fencing off land is the only way to attract tourists accustomed to cattle-free bird-watching.

The costs of fencing--about $5,000 a mile in the United States--and seeds for the proposed hummingbird sanctuaries in Mexico are being partially defrayed by groups like the Nature Conservancy, said Tere De Soto, ecology coordinator for the city of Naco.

The observatory and the Naco government are training locals to be tour guides for the bird-watchers.

Organizers are also working on a tour package that would let birders stay at ranchers’ homes, allowing them to combine their passion for birds with a weeklong taste of Mexican culture.

A balance of tourism and land conservation, difficult enough north of the border, is even more complicated in northern Mexico, said Juan Caicedo, conservation and outreach associate at the observatory.

Northern Mexico has plenty of hummingbirds, but virtually none of the infrastructure--bed and breakfasts, cozy hotels and guided tours--that hummingbird watchers in Arizona expect.

Caicedo travels almost every week to visit Mexican ranchers in an attempt to convince them that money can be made by revamping parcels of their land in the American model.

“We sit in their kitchen and talk about their particular piece of land, and how it fits into the big picture,” Caicedo said. “They always get real excited when they find out that millions of birds come through their land on their way north and south.”