El Tigre Expediton

Click here for the El Tigre Expedition slideshow

I recently traveled to Mexico on behalf of the Overland Society to assist a team of scientists and volunteers with the El Tigre Expedition in northern Sonora, Mexico. The expedition was part of the MABA program (Madrean Archipelago Biodiversity Assesment) headed by the Sky Island Alliance based in Tucson, Arizona. The project is a tri-national effort involving people from the U.S., Mexico, and France with a goal of studying and documenting a 70,000 square mile region of the Southwestern United States and Northwestern Mexico containing the “sky island” mountain ranges that are home to rich and diverse eco-systems unique in the world.

Tom Van Devender's improvised field office
Tom and Ana Lilia's improvised field office in the Pilares de Teras ruins

The Sierra El Tigre is one such sky island in northern Sonora associated with the western flanks of the massive Sierra Madre mountain ranges where tropical and temperate climates intersect. They don’t call it the “El Tigre” for nothing; this is the land of the jaguar, ocelot, and mountain lion. Aside from a large mining operation in the early part of the 20th century, the range is mostly unpopulated and remote. Only a couple of previous scientific expeditions have been undertaken in these mountains, and as a result, they are largely understudied. The data collected for the MABA program will be used by several agencies (including those among the Mexican government) to inventory and manage the resources involved.

El Tigre Mine ruins
Ruins at the El Tigre Mine

I met with my friends and fellow Overland Society volunteers, Dale and Shirley Durham, and we assisted the group by providing 4WD transport for gear and people, extra fuel and water, technical support for 4WD logistics including trail repairs and guidance through technical road sections, photographic documentation, navigation and computer mapping support, and general assistance where needed.

Bavispe river crossing
Crossing the Rio Bavispe

The MABA group included several staff from Sky Island Alliance, CONANP (Comision Nacional de Areas Naturales Protegidas - Mexico’s agency for national parks and preserves) along with volunteers from the University of Sonora and the University of Arizona, and two photojournalists from Sonora Es magazine.

The trip was a great success with many mammal, bird, insect (and even a few reptilian) specimens noted, and over 700 plant species observations and 500 plant collection specimens. According to Tom Van Devender, the project manager, this was the first major plant inventory in the Sierra El Tigre since the University of Michigan expedition led by Stephen S. White in 1938-41.

Sonoran moth species
One of two boxes of moth specimens collected by John Palting



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