Saving IBAs: Southern Sierras

This month we introduce a new series featuring conservation projects encompassed in our Saving Important Bird Areas Initiative, one of the strategies through which the organization is working to conserve crucial birds and habitats. Through this initiative, we direct our focus towards the Important Bird Areas projects which could benefit from national level attention and increased science support. In recent months, national Important Bird Areas staff have been working in coordination with state and local chapters, providing support to these projects by performing spatial analysis, mapping, compilation and summarization of data, as well as coordinated planning.

Photo by Andrea Jones

Today, we highlight the Southern Sierras project, which encompasses four IBAs -South Fork Kern River Valley, Tehachapi Mountains, Kelso Creek,  and Southern Sierra Desert Canyons- nestled in the southern Sierra Mountains at the confluence of two mountain ranges, the Central Valley, and the Mojave Desert. This unique physiography makes the region popular for wind developers, who seek to take advantage of the funneled winds along the foothills of the mountains, building large wind farms. The region is also a rich area for birds, with populations of breeding Southwestern Willow Flycatcher and Yellow-billed Cuckoos along the Kern River. The relatively lush mountain canyon act as migratory stopover sites for northbound songbirds in the spring and mountain ridges carry raptors south in the fall. In addition, California Condors range within this region, particularly in the Tehachapi Mountains.  With these conflicting uses of land, the need to properly site wind to minimize bird mortality is crucial. However, this is a remote region and data on bird abundance is sparse. In an effort to provide siting guidance on wind development projects, National Staff worked with Audubon California and Kern River Preserve staff to help identify existing data that could be used to provide input on wind development siting.

Map of rectified NEXRAD data combined with eBird data.

Data from a recent US Army Corps RADAR study, which was designed to help prevent bird strikes at Air Force bases, for the China Lake NEXRAD station was rectified and mapped to display areas of spring migration hotspots in the region. In addition, eBird data helped fill in additional gaps, primarily showing areas popular with birders seeking to find concentrations of spring migrants in the region. Through this process of rectifying and aggregating data, a number of areas critical to bird migration in the southern Sierras were identified for the first time. Identifying these new hotspots helps local Audubon staff members in planning meetings, where they are working to divert wind development projects to areas that are less important to birds. Data gaps remain in the region, but the efforts described here have helped identify areas in need of more information. Audubon California is now seeking funding to use targeted mobile RADAR research to fill in data gaps at the Southern Sierra IBAs, which will help quantify the number of migrants using sites in wind development areas, identify the timing of migration both seasonally and daily, and possibly understand the altitudes at which birds are flying.