None The Nature Conservancy in Arizona Press Releases Search All Press Releases Tamera Skrovan Phone: (602) 322-6996 E-Mail: tskrovan@tnc.org

Good Management Saving Endangered Birds

Tangible Conservation Success for the Conservancy's San Pedro River Preserve

Two years ago, The Nature Conservancy purchased the 2,150-acre Three-Links Farm on the San Pedro River, north of Benson, Arizona. This farm has six miles of cottonwood-willow riparian habitat.  Historically, 1,000 acres of the farm had been used for irrigated agriculture---pumping about 3,500 acre feet of water each year. As a result, the San Pedro River no longer flowed year-round on the farm, or for miles beyond its boundaries.

Today, by retiring groundwater pumping, the Conservancy has restored perennial surface flow along three miles of the San Pedro River.  Additionally, the lower stretch of the San Pedro River now accounts for more than 40% of known southwestern willow flycatchers in the state.  According to a recent status report from U.S. Fish & Wildlife Service, our work is contributing directly to the recovery of this endangered species.  “Continuing regeneration of habitat along the San Pedro contributed to a large increase in flycatchers…the increase in flycatchers at Dudleyville Crossing occurred exclusively on The Nature Conservancy’s San Pedro River Preserve section of this site,” the report stated.

The San Pedro River and its tributary streams top the list of the most precious riparian (streamside) habitats in the Sonoran Desert and have earned the Conservancy’s designation as one of the Last Great Places on Earth. An estimated 60 to 75 percent of Arizona's wildlife species depend on riparian habitats, but most of the state’s riparian habitats have been degraded or lost altogether in the last century. The San Pedro River's riparian area is one of the last and one of the healthiest. This river is unusual, too, because it flows northward for 140 miles from Mexico into Arizona. Towering Fremont cottonwood-Goodding willow forests (the rarest forest type in North America) and mesquite bosques (another rare forest type) line its banks and form a green ribbon of life through the desert.

Millions of birds—representing 345 species, or nearly half of the entire North American bird fauna— depend on this desert oasis to survive. Thirteen species of breeding raptors (birds of prey like hawks and owls) are found there, one of the most diverse concentrations of breeding raptors in North America.

The river also hosts more than 80 species of mammals, 40 species of reptiles and amphibians, 100 species of butterflies, and 20 species of bats. (For more information about the diversity of life in the San Pedro, please visit our Last Great Places website at lastgreatplaces.org and click on the San Pedro River or go directly to the San Pedro River section).

Said Pat Graham, director of the Conservancy’s Arizona chapter, “The Nature Conservancy’s Three-Links Farm acquisition project is a significant part of the Conservancy’s longstanding program to protect the San Pedro River by reducing groundwater pumping, restoring native habitat and improving natural flows in the river.” Since 1990, in the northernmost 85-mile section of the San Pedro alone, the Conservancy has protected thousands of acres of riparian forest habitat and retired water use amounting to approximately 5,800 acre-feet per year. The Three-Links Farm water-use retirement will bring the total amount of agricultural water use retired on the lower San Pedro to 8,800 acre-feet. [An acre-foot equals 325,851 gallons, enough water to cover one acre (about the size of a football field) to a depth of one foot. One acre-foot can supply three families with water for one year. Source: Marin Municipal Water District, CA.]

The Three Links Farm contains more than six miles of the river and rare cottonwood-willow riparian habitat. With more than 3,500 acre-feet of water pumped annually for irrigated agriculture in recent years, the San Pedro River no longer flows year round on all of the farm, or for miles downstream. According to Dave Harris, the Conservancy’s Lower San Pedro Program Manager, "Our hydrologic modeling shows that by retiring approximately 850 acres of irrigated agriculture this project alone could reestablish year-round flow in 14 miles of the river that is now dry most of the year and enhance existing flows in another six miles of river. Our experience shows that these additional miles of the river can recover to extremely high-value Fremont cottonwood-Goodding willow forest."

The Conservancy will also restore about 1,000 acres of the farmlands to low-water-use native grassland habitat on both sides of the river. Native grasses will hold soil in place and both prevent erosion and enhance water absorption. At the Conservancy’s San Pedro River Preserve near Winkelman, about 250 acres of river terrace lands are being restored to native grasses with help from volunteers from Volunteers for Outdoor Arizona and INTEL Corporation. Near the preserve, another conservation easement and partnership project area at the Southwest Wildlife San Pedro River Sanctuary, is retiring 305-acres of irrigated agriculture to enhance about 4 miles of flow in the river and is restoring native habitat to degraded farmlands.

To accomplish conservation goals on the Three Links Farm, the Conservancy purchased the property and placed a conservation easement on the land, a legally binding agreement that, typically, permanently prohibits intensive residential development, protects native habitat, and restricts groundwater use. The terms of this conservation easement also include a provision for The Nature Conservancy to restore native habitat in disturbed areas. The Conservancy sold a conservation easement to the U.S. Bureau of Reclamation for a 1,420-acre portion of the farm. This both satisfies Bureau mitigation requirements to protect native fish and provide the essential public partnership needed to achieve this private conservation initiative. The Conservancy retains the conservation easement on the remaining 736 acres. With the conservation easements in place, the Conservancy seeks conservation buyers for up to five parcels ranging in size from 275 acres to 600 acres. Some parcels include existing houses, corrals and other facilities.

The northern San Pedro River (called “lower San Pedro River” due to its northerly flow)—where the Three Links Farm, the Conservancy’s San Pedro River Preserve, and the Southwest Wildlife San Pedro River Sanctuary (another conservation easement project) are located—contains some of the best riparian habitat remaining in the Sonoran Desert ecoregion. Some of the best cottonwood-willow riparian forest and mesquite bosque remaining in the Southwest is found here. It is a haven for wildlife, including native fish, migratory birds, and other birds like the federally listed endangered southwestern willow flycatcher. Among the wildlife species found on the Three Links Farm site are: a healthy population of native lowland leopard frogs, a native fish called the longfin dace, zone-tailed hawks, yellow warblers, and the rare yellow-billed cuckoo.

In summary, Pat Graham said; “We can restore this river for wildlife and for people. Returning water will give the river life and sustain the millions of birds that follow its course every year. The same river supports family farms and provides water to local communities downstream. By selling the property to buyers who cannot build subdivisions along the river, we ensure the river will remain healthy and vital forever. It also makes good business sense for us to recover our investment, so we can protect other special places in Arizona.”