May 4 - May 10, 1995

Swamp Thing

By Kevin Franklin

When you are courting a nice girl an hour seems like a second. When you sit on a redhot cinder a second seems like an hour. That's relativity.

--Albert Einstein

IN KEEPING WITH Al's observations on relativity, when you're a small swamp in Louisiana, people want to fill you with dirt. When you're a small swamp in southern Arizona, they make a wildlife refuge out of you.

Location, location, location as the real estate people say.

In many other parts of the world, the Arivaca Ciénega springs and associated marshland would be a minor natural phenomenon. Here in the desert, it provides an oasis of immeasurable value. As time passes, developments grow and groundwater is mined, this value only grows.

Before Europeans arrived on the scene, hydrologists estimate only five percent of Arizona qualified as riparian--or water-associated habitat. Since then, 90 percent of that five percent has been destroyed, leaving us with less than half a percent of the state as riparian. Conversely, according to Arizona State University Center for Environmental Studies figures, 60 to 75 percent of Arizona's wildlife species are dependent on riparian areas.

That leaves those few areas, like Arivaca Ciénega, as the ultimate in prime real estate.

Fortunately, the marsh was purchased by the U.S. Fish and Wildlife Service in 1985 and flourishes under the Service's protection as part of the Buenos Aires National Wildlife Refuge.

Even among riparian areas ciénegas are rare, says Thea Ulen, the refuge's outdoor recreation planner.

The combination of natural springs, shallow bedrock and impermeable soil preventing water from soaking into the water table creates a ciénega, she says.

Arivaca is the westernmost of these particular habitats, she notes.

Ciénega literally translates to "100 waters" in Spanish, but generally means swamp or marsh. The Arivaca Ciénega is fed from seven springs in and nearby the marsh.

Birders consider the ciénega one of the best locations in the Southwest for a wide variety of avian life. More than 290 bird species have been spotted on the refuge. Gray hawks, tropical and thick-billed kingbirds and vermilion flycatchers are among some of the headline species.

Only 50 to 80 pairs of gray hawks live in the United States, Ulen says.

"We have seven pairs on the Arivaca drainage," she notes. "That's 10 percent of the entire U.S. population."

More of the raptors live in Mexico, but their status as a stable population is uncertain, she says.

Since mucking through the marsh makes for difficult going and damages marsh life, wooden boardwalks have been constructed throughout the ciénega.

During the summer of 1993, members of the federal Youth Conservation Corps built one section of the boardwalk. The following summer a contractor built the rest. This year plans are in the works for an observation deck, fixed binoculars and identification tiles, Ulen says.

From the existing boardwalks and two miles of trail, visitors can quietly observe the scores of birdlife living in or stopping at the rare water source.

The best way to do this trip is to arrive just after lunchtime and stroll along the boardwalk admiring the diurnal birds and soaring raptors. As the day passes, the flycatchers and birds more active at dusk emerge. Bring a good bird guide like Peterson Field Guides' Western Birds or the National Audubon Society Field Guide to North American Birds.

Birds aren't the only attraction here. Tracks from coyotes and coatimundi hunting the night before can be seen along the boardwalk. Along certain sections of the ciénega, giant bullfrogs leap into deeper water as visitors pass. Unfortunately, the bullfrogs have been devouring native species like the Chiricahua leopard frog. The hapless leopard frogs have been forced into retreat to a secluded pond on the south end of the refuge.

More threatening to the ciénega as a whole is a drop in the amount of available water. Historically, Arivaca Lake flowed into the marsh, but it's now dammed. Refuge staff monitor the groundwater levels, and they're three years into a 10-year study of water flow into the ciénega from neighboring drainages. The study will establish water rights for the refuge just like any local ranch has.

"We want to ensure a certain amount of water goes through there," Ulen says.

The study applies only to surface water, however. Groundwater, the source of the springs, is another matter.

Ulen says the groundwater level has remained constant so far.

Overlooking the cattails and cackling red-winged blackbirds on the western edge of the ciénega, the small town of Arivaca, population 2,000, comes into view. Currently, the town's groundwater mining is probably sustainable. But with developments at nearby Rio Rico in full swing, one has to look at the little valley and wonder how long before Arivaca Ciénega becomes threatened by slick developers in pursuit of another piece of Arizona to suburbanize.

It's tough to hold onto good real estate, especially for non-humans.

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