The site is located between the Patagonia and Santa Rita mountains in a verdant floodplain valley. Sonoita creek is a perennial stream that transverses the length of the preserve. The natural flooding processes are still mostly functional. The creek is spring fed and partially augmented by the city of Patagonia?s water treatment plan. Open April-September: Wednesday-Sunday, 6:30 a.m.-4 p.m. and October-March: Wednesday-Sunday, 7:30 a.m.-4 p.m. 60 miles southeast of Tucson. Take I-10 east to Highway 83 exit south. At Sonoita, turn west on Highway 82. In Patagonia, turn west on 4th Avenue. Turn south on Pennsylvania, cross the creek, and go about one mile to the entrance.
Closed: Mondays & Tuesdays all year & on Thanksgiving, the day after Thanksgiving, Christmas & New Year?s Days.
The Patagonia-Sonoita Creek TNC Preserve is extremely important avian habitat for supporting an exceptionally diverse assemblage of riparian associated bird populations, and densities of nesting individuals of these populations. Over 275 species have been recorded, and considering just the University of Arizona and the Audubon IBA Program surveys we detected 92 species (n = 9 surveys, Feb. 2007-Aug. 2008). Together we detected eight special conservation status species, which qualifies this site under the Arizona IBA criterion, Site Important to Special Status Avian Species.
Certain species of conservation concern breed and nest within the Preserve in very dense numbers. Gray Hawk (AZGFD-SGCN T1b, 5 occupied territories in 2007), Yellow Warbler (USFWS BCC 2008, high of 12.7 detected /km, 3/31/08), Lucy?s Warbler (Audubon WatchList-Yellow listed, 12.7 detected /km, 3/31/08), Abert?s Towhee (Audubon WatchList-Yellow listed, 9.5 birds/km, 08/30/08), and Bell?s Vireo (Audubon WatchList-Red listed, 3.2 birds/km, 08/30/08), exhibit very high densities (migration and nesting). Other species of concern also occur in the preserve, including, Northern Beardless-Tyrannulet (USFWS BBC 2008, 76.4 birds/km2, 05/29/07),Yellow-billed Cuckoo (AZGFD-SGCN T1a, 17.0 birds/km2, 06/21/07), and Black-bellied Whistling-Duck (AZGFD-SGCN T1), which commutes to foraging areas locally. One heron species, the Great Blue Heron (not a special conservation status sp., 8.4 birds/km, 03/31/08, and 4 active nests in 2008), nests in the cottonwood gallery forest in most years.
This site also meets the AZ IBA criterion, Rare, Unique, or Exceptional Representative Habitat/Ecological Community, as it supports the full suite of Arizona riparian obligate breeding birds, for the 4000 foot elevation of where it is located, including (all birds mentioned above, plus): Common-Ground-Dove, Broad-billed Hummingbird, Black-chinned Hummingbird, Acorn Woodpecker, Western Wood-Peewee, Black Phoebe, Vermilion Flycatcher, Dusky-capped Flycatcher, Ash-throated Flycatcher, Brown-crested Flycatcher, Cassin?s Kingbird, Bridled Titmouse, Bushtit, White-breasted Nuthatch, Bewick?s Wren, Phainopepla, Common Yellowthroat, Yellow-breasted Chat, Summer Tanager, Song Sparrow, Northern Cardinal, Black-headed Grosbeak, Blue Grosbeak, Lazuli Bunting, Hooded Oriole, Bullock?s Oriole, and Lesser Goldfinch (not including many riparian associated migrant and over-wintering avian species).
The primary factor for this diversity is the riparian forest and surface water, and nearness to Sierra Madre Occidental avifauna community stretching up from Mexico. A geologic fault causes the ephemeral Sonoita Creek to rise in this reach of creek, and the well developed floodplain has allowed extensive tree and shrub development, including vines and understory forbs. Add to the mix an upland mesquite bosque, a cienega, and a Sacaton grassland complex, and you have the patchiness of different vegetation communities all adjacent to each other, to further enhance the vegetation community mosaic, and provide the abundance of local niches to support the extremely diverse local avian community. Disturbance by humans has been limited, i.e., there is no grazing or motorized vehicle use of the creek banks, and this oasis of riparian ecosystem has become one of the most productive avian nesting areas in Arizona. In very recent years (2008 and 2009), more species of the southern Sierra Madre Occidental have found this habitat, and occupied the site for periods, they include the Sinaloan Wren (8/25/08-11/03/09), Rufous-capped Warbler (06/04/09-09/04/09), Plain-capped Starthroat (Aug. 2009), and Black-capped Gnatcatcher (Nov. 2009). The value of the site increases through time with more use of the Sonoita Creek valley upstream for local housing which is expanding and with continued downstream grazing. The biodiversity of avian fauna supported here is critical if climate change causes other riparian areas under greater human strain, to dry and become more ephemeral in their surface water availability.
Drainage: The drainage from the town affects the watershed?s health. Pollutants and sediments have the potential to damage the stream ecology. Conservation easements and other applicable tools are used to protect upstream parcels. The Conservancy also maintains an open and ongoing dialogue the Town of Patagonia, local conservation groups, and residents within the watershed regarding water issues.
Groundwater abstraction: There is a threat of the town pumping the water that would other wise flow through the preserve. The Nature Conservancy maintains relationships and contact with the land owners and conservation groups to maintain the water flow.
Consequences of animal/ plant introductions: There are a number of aquatic and terrestrial invasive species. The preserve actively manages these species through removal processes.
Construction/ impact of dike/ dam/ barrage: The development of up stream land threatens the preserve. Old construction from the rail bed has been an impediment to natural stream dynamics and may be a factor in the reduced recruitment of riparian trees along the altered active channel. There is nothing be done to manage this problem.
The area is managed as a natural preserve by the Nature Conservancy. Active management is occurring for grassland restoration, fuels reductions and future prescribed fire use, invasive species (>7sp.) management, and cienega restoration.
The site is located in a riparian transition zone between low and high elevation types. The riparian habitat contains large, old Cottonwoods and Gooding Willows. Other vegetation species are Arizona Black Walnut, Velvet Mesquite, Velvet Ash, and Canyon Hackberry. Within this site cienagas (wetlands) can be found.
Currently the land is a managed nature preserve. Prior to Nature Conservancy ownership, the creek and floodplain parcel was owned by a railroad company that leased out the fields adjacent to the line for agricultural and pastoral use. The rail bed has been an impediment to natural stream dynamics and may be a factor in the reduced recruitment of riparian trees along the altered active channel. Previous agricultural and pastoral use of the floodplain brought a host of invasive species. The preserve was established in 1966 with the parcel purchased from the railroad company the preserve has expanded over the years through the donation and purchase of adjoining parcels.