For more than a decade, Raise the River—a binational coalition of NGOs that includes Audubon—has been restoring habitat in the Colorado River Delta. A new publication shows how additional efforts can optimize sites for restoration where it provides the highest benefits for birds, offering insight for efficient restoration that can remove forecast and reduce implementation costs. Not only will this have benefits for birds, habitats, and communities in the Colorado River Delta, but it could allow for every drop of water and every dollar in the Colorado River Delta to be used more strategically—a welcome advance. in an excessively extended. river with many interests and tradeoffs constantly in play.
Due to a century of upstream water development, the Colorado River has not flowed for its last 100 miles, effectively eliminating the Delta’s vast, lush ecosystem of riparian forests and wetlands. Notably, birds such as the Willow Flycatcher and Song Sparrow experienced population declines, and six additional species were locally depleted. Degradation and loss of riparian forest is a major factor driving these declines.
In partnership with the US and Mexican federal governments under the terms of successive treaty agreements (Minute 319 and Minute 323), Raise the River combines engineered water delivery and reforestation in the Colorado River floodplain to reconnect the Colorado River ecosystem from the US-Mexico border where it drains, to its mouth in the Upper Gulf of California.
The new study published in the Journal of Environmental Mangement and led by the National Audubon Society in collaboration with Mexican partners at Pronatura Noroeste and US partners at the United States Geological Survey, US Bureau of Reclamation, University of Arizona, University of Colorado , and Cornell Lab of Ornithology, sought to strategically prioritize locations for riparian forest restoration based on their importance to priority birds. In addition, given the high cost of active restoration, the study aims to estimate the extent of landscape restoration needed to maximize bird community abundance and diversity.
Rather than relying on non-ecological factors such as irrigation costs, the study used a data-driven approach, using machine learning and systematic conservation planning techniques. By predicting bird distributions in simulated landscapes with different restoration scenarios, the research identified the most important locations for restoration. The authors combined bird and plant survey data collected by Pronatura Noroeste, with high-resolution land cover maps produced by partners at the University of Arizona, to enable accurate predictions, which allowing for the strategic allocation of resources to maximize the benefits of restoration efforts.
Stefanny Villagómez, expert avian Conservation Biologist with Pronatura Noroeste, said, “Audubon’s analytic expertise, together with Pronatura Noroeste’s extensive record of monitoring data, has allowed us to develop an innovative restoration strategy that should improve outcomes for birds.”
This analysis represents the first data-driven, strategic restoration study for the Colorado River Delta. By aligning restoration efforts with predicted bird distributions, the ultimate goal of this research is to provide decision support that will help revive once-vibrant bird communities and restore balance to this threatened ecosystem. . Future research could extend this analysis to other regions in need of restoration.
Minute 323, the current binational Colorado River Treaty agreement—which includes commitments for environmental restoration—expires in 2026. While decision makers in the US and Mexico are negotiating a new agreement, this new publication provides a roadmap for targeting restoration to improve outcomes for focal bird species. , optimizing restoration investments, and ultimately for allocating funding to monitoring and science that provides a strong return on investment.
