Residents of the Rio Cocospera river valley and the town of Imuris were shocked to learn of a huge project already under construction in late 2023. This project is a brand new railway segment from the Imuris area to Nogales, but further east than the current railway, cutting through the beautiful, biologically important, and little-disturbed Rio Cocospera drainage.
Rio Altar near Oquitoa, Sonora around 2013. The Rio Altar is the westernmost Sonoran creek with perennial water, until the Rio Sonoyta, which has very little, if any, perennial water left.
This valley has had small-scale agriculture for many decades, but recently started seeing huge nut tree farms by big ag, which could spell doom for the surface water and groundwater, and potentially some of the riparian gallery forests as well. There are still large stretches of cottonwood and willows forests that depend on the shallow groundwater of this valley bottom.
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 beavers colonized, I found higher bird abundance and richness of bird groups such as all breeding birds, insectivorous birds, and riparian specialists, and higher relative abundance of many individual species—including several avian species of conservation concern.
The status of beaver (Castor canadensis) in northeastern Sonora, Mexico, is uncertain. We surveyed the Cajon Bonito River to assess the beaver’s status and habitat and found five colonies. Limiting factors appear to be pollution due to animal waste, deforestation of riparian trees, and human exploitation. Beavers did not appear to require habitat diversity as much as dense riparian and aquatic vegetation in waters with low organic content. These kinds of studies are imperative to understanding the natural history and ecology of the species in this unique region.
Lacey Anderson departs Bacerac in northern Mexico and heads out on her favorite type of adventure: running undiscovered rivers. Faced with pending monsoons and little beta, she unveils the reasons she loves multi-day expedition trips.
A story has been written and posted about this trip - see the Rio Tutuaca photo gallery here.
On August 7, 2014 ten million gallons of a mining wastewater solution broke through containment at the Buenavista copper mine just outside of Cananea, Sonora. The sulfuric acid solution was released into the Rio Bacanuchi, a tributary of Rio Sonora, one of the largest watersheds in Sonora.
