Since the late 1990s, Audubon and Audubon California have been involved in helping shape policy regarding the Salton Sea, California’s largest lake and a key stopover for millions of birds each year. Southern California Audubon chapters – particularly the San Diego Audubon Society – initially drove this involvement and continue to be active promoting conservation concerns at this important site.
The Salton Sea is one of the state’s most important bird habitats, and it has long been a vexing conservation issue. As water has been siphoned off or agricultural and urban use, dust emissions have increasingly threatened public health and dramatically altered the quality of the water that migrating shorebirds rely upon for survival.
Salton Sea is home to at least 19 sensitive species including Brown Pelican, Least Bittern, White-faces Ibis, Wood Stork, Clapper Rail, Long-billed Curlew, and many others.
The conservation issues at Salton Sea are several. Increased salinity of the water regularly depletes food for birds. Disease, contamination and human encroachment are other major concerns. There have been several major die-offs of birds at the location, with major recent kills including 150,000 Eared Grebes in 1992, 9,000 White Pelicans in 1996, and more than 11,000 waterbirds in 1998.
Making matters worse has been decades of inaction on the part of policymakers. A 2003 agreement with the federal government to allow California to use the Salton Sea to transfer Colorado River water from Imperial Valley to San Diego complicated the issue tremendously. Although California agreed to provide for habitat restoration and dust mitigation, the state has yet to follow through on these promises, and the situation at Salton Sea has only gotten worse.
Burrowing Owls in Imperial Valley
Just south of the Salton Sea lies the Imperial Valley, home to about 70% of the state's breeding Burrowing Owls, or about 4,000 breeding pairs. The population of this small bird has been in sharp decline over the last 50 years. No one factor has been implicated in its decline, but the cumulative impacts of human activities have certainly contributed. Farming and renewable energy development both pose risks to this bird's habitat in the Imperial Valley.
Audubon California, with the support of the Imperial Valley Community Foundation, has created a publicly available, interactive map that consolidates Burrowing Owl survey data from the past decade in Imperial Valley. The map includes supporting layers such as renewable energy projects, crop types, irrigation canals and drains, and more. We encourage you to explore the map and learn more about this region, so critical to Burrowing Owls in California.
Maps such as these have allowed researchers to learn about Burrowing Owls in the Imperial Valley. This information can be used to help prioritize future conservation areas, and to identify information gaps and areas not yet surveyed. Here are a few fun facts, revealed by scientists studying survey data collected by the Imperial Irrigation District (IID):
- Burrowing Owl abundance is best predicted (from among many environmental variables) by the number of available burrows and the presence of alfalfa. Alfalfa happens to be the one of the most common crops in the Imperial Valley.
- Burrowing Owls nest almost exclusively within or along irrigation drains, canals, and ditches, particularly earthen drains.
A larger version of the map is available here.
Note: GIS users who wish to access the underlying data may do so by following the steps below:
- Open the Layer List (the 2nd button on the left side panel).
- Find the layer of interest and select the drop-down arrow to the right of its name.
- Select "Show Item Details" from the drop-down menu. This will open a new page that includes metadata for the layer of interest, and any related layers.
- On this new page, you can click the Open button, which brings up a drop-down menu. In this menu, select "Open in ArcGIS for Desktop". This downloads a file that you can open in ArcMap.
- In ArcMap, you are still accessing the online layer. If you'd like to save your own copy, you can right click on the layer in the Table of Contents and select Data > Export.