Reports and Journal Articles

Jaguars are endangered in Mexico and the United States, necessitating careful monitor- ing of population status. We determined minimum numbers of jaguars and sympatric pumas in a small population in northern Sonora, Mexico, the nearest known… See more

Created as part of a collection of Arizona river overview documents titled "River of the Month Series, Celebrating Arizona’s Rivers". These reports were prepared and supported by Environmental Defense Fund, Sonoran Institute, Sierra Club, Grand… See more

The Río Yaqui river basin (RYRB) is the largest in northwest Mexico, both in terms of area and volume of flow. Water resources in the region are under increasing stress due to intensive use for agriculture and urban growth, compounded by climate… See more

I measured bird abundance and richness along the upper San Pedro River in 2005 and 2006 to investigate how beavers (Castor canadensis) may act as ecosystem engineers after reintroduction to a southwestern U.S. desert riparian area. In areas where… See more

Known from only a handful of localities in the Sierra Madre Occidental of western Mexico, the Spotted Box Turtle, Terrapene nelsoni (Family Emydidae), remains one of the least known chelonian species of North America. Only at the type locality and… See more

Oct. 5th, 2011 finding by the U.S. Fish and Wildlife Service that the cactus ferruginous pygmy-owl (Glaucidium ridgwayi cactorum) does not warrant protection from the Endangered Species Act. "We, the U.S. Fish and Wildlife Service (Service),… See more

For thousands of years, rivers in the arid Southwest have sustained people and supported an abundance of plants and wildlife. Though at times unnoticed, the numerous services that these rivers perform provide substantial benefits to the people… See more

Details of trip taken to Sonora in March 2011 in search of the masked bobwhite, which is on the brink of extinction in the wild in Sonora as of 2011.

Fire is a dominant ecological process in almost all landscapes of La Frontera. Fire histories from throughout the region on the United States side of the border show that, before circa 1900, extensive surface fires occurred within pine-dominant… See more

Investigative Report: Macho B, January 19, 2010This report contains information that has been redacted pursuant to 5 U.S.C. §§ 552(b)(2), (b)(6), and (b)(7)(C) of the Freedom of Information Act. Supporting documentation for this report may be… See more

Situated in the topographically complex transition between the Neotropics and the temperate biomes of North America, the state of Sonora, Mexico, has an extraordinarily diverse herpetofauna. Surprisingly little research has been conducted on the… See more

For thousands of years, people in the arid West have built their communities near rivers that supply drinking water, serve as navigation corridors, and support hundreds of plant, fish, and wildlife species. The Upper Santa Cruz is such a river,… See more

Devil’s Canyon is located in Pinal County Arizona approximately 6 km east of the town of Superior in the Globe Ranger District of the Tonto National Forest. The area is generally rugged with deep canyons and is defined by its complex rock formations… See more

There is general interest among fire ecologists to integrate observed fire regimes into long term fire management. The United States-Mexico borderlands provide unique research opportunities to study effects of contrasting forest management… See more

The goal in traveling to the Sierra El Tigre - one of the most extensive of the sky islands - was to complete a basic bio-geographical assessment of the area, listing species of flora and fauna present in the Sierra El Tigre and especially “… See more

Based on collections and published reports, the herpetofauna of mainland Sonora, México, includes 37 amphibian and 139 reptile species. An additional two amphibian and five reptile species have been taken very near the Sonoran border in contiguous… See more

Canotia holacantha Torrey is reported from the Gulf of California, Mexico on Isla Tiburón. This population is isolated from its closest conspecifics in northern Sonora by 230 km and is best explained as a Pleistocene relict. Previous reports of… See more

Spanish travelers or settlers in Santa Cruz County until 1691 when a Jesuit missionary, Father Eusebio Francisco Kino carne to the valley to establish missions and convert indigenous populations to Christianity. The impact Father Kino had on Santa… See more

Renewed botanical interest in the Sonoran islands of the Gulf of California (Islas Tiburón, San Esteban, San Pedro Nolasco, Dátil, and Alcatraz) as part of our project, “Botanical Diversity of Isla Tiburón and Satellite Islands, Gulf of… See more

Devil’s Canyon is located in Pinal County Arizona a few miles east of Superior in the Globe Ranger District of the Tonto National Forest. The area is extremely rugged with deep canyons, rocky ridges, and uplands dominated by large boulders and… See more

Development proposals sneak up on remote and unsuspecting towns in the Gulf of California region, such as Bahia Kino, Santa Rosalillita, Bahia de Los Angeles, El Golfo de Santa Clara, Puerto Libertad, and Punta Colonet. Many of the residents have no… See more

The Center for Biological Diversity and Defenders of Wildlife hereby formally petition the U.S. Fish and Wildlife Service (also “Service”) to list one of the following entities of cactus ferruginous pygmy-owl: 1) the Arizona distinct population… See more