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Birds and the Salton Sea. An exploration of the importance of the Salton Sea and associated ecosystems to birds: a global and regional perspective Presented to: California Water Dialogue Sept. 16, 2003 Los Angeles Daniel S. Cooper, M.Sc. (University of California, Riverside)
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Birds and the Salton Sea An exploration of the importance of the Salton Sea and associated ecosystems to birds: a global and regional perspective Presented to: California Water Dialogue Sept. 16, 2003 Los Angeles Daniel S. Cooper, M.Sc. (University of California, Riverside) Director of Bird Conservation Audubon California Pasadena
Birds and the Salton Sea • Habitat diversity in the Lower Colorado River Valley (“LCR”) ecosystem • Rare vs. rare • Defining the Salton Sea avifauna (= birdlife) • Outlook for Salton Sea avifauna, and what Audubon is doing to help
Key bird habitats of the Salton Sea/LCR Valley (in no order) • Shallow, open water • Salton Sea, northern Gulf of California • Islands • Freshwater/brackish marsh • LCR and tribs.; seeps in large canals; unlined smaller canals • Mudflat/Impoundment • Mainly South End Salton Sea • Mesquite Bosque • Algodones Dunes, Lower Colorado River Valley • Cottonwood/Willow Woodland • Lower Colorado River Valley, Locally in Imperial Valley • Agricultural fields • Mainly Imperial and Mexicali Valleys; locally elsewhere
Rare vs. “rare” • Species formerly common in California, now declining or lost entirely • Generally due to habitat loss • e.g. Burrowing Owl, Mountain Plover • Species formerly absent or in low numbers; now present but still rare • Due to habitat alteration or climate/global change • e.g. Gull-billed Tern • Species never common in California, and only occurring as vagrants • Chased by bird-watchers; of low conservation concern
The Salton Sea avifauna • Lower Colorado River (“LCR”) Endemics • “Last Stand” breeders/winterers • Winter congregants • Summer dispersers • Passage migrants • Vanishing (vanished?) nesters
Lower Colorado River “Endemics” • Confined to extreme northwestern Mexico, western AZ, southern NV and southeastern CA • “Yuma” Clapper Rail • “Van Rossem’s” Gull-billed Tern • Abert’s Towhee • “Salton Sea” Song Sparrow • “Large-billed” Savannah Sparrow Clapper Rail Gull-billed Tern
“Last Stand” Breeders/Winterers • Mountain Plover • 30-40% Global population in Imperial Valley (formerly widespread) • Burrowing Owl • 70% of California pop. in Imperial Valley • Associated with agricultural fields • 60% of CA population lost in 1980s • Western Snowy Plover • Largest wintering concentration in interior of U.S. • Major interior-U.S. breeding site
Winter congregants • Begin arriving late July/August – November • Occur in two main roles: • Agricultural fields • Largest agricultural/grassland area in southern California • The Salton Sea itself • Largest and shallowest body of water in California
Winter congregants… (agricultural) From left: Sandhill Crane, Long-billed Curlew, White-faced Ibis One of just 3 crane wintering areas left in SoCal (formerly common) 20K+ curlews wintering each year 40K ibis wintering each year Bob Miller
Winter congregants… (the Salton Sea itself) Up to 75% of N. Am. pop. passes through in early spring (from Gulf of CA to Great Basin) 1.5 million birds in winter David Blevins Bob Miller “Lost” shallow water lakes: Tulare Lake, Owens Lake, San Jacinto Lake Buena Vista Lake; plus most coastal wetlands south of SF Bay…
Winter congregants… (the Salton Sea itself) Black-necked Stilt Am. White Pelican American Avocet 100+ miles of shoreline 10s of thousands of shorebirds on shoreline and adj. impoundments 30% of Global AWP pop. David Blevins Bob Miller “Lost” shallow water lakes: Tulare Lake, Owens Lake, San Jacinto Lake Buena Vista Lake; plus most coastal wetlands south of SF Bay…
And lots in between… Freshwater impoundment at the edge of the Sea (southeast corner) c. 30,000 Snow and Ross’ Geese 100,000+ other waterfowl David Blevins Bob Miller RichardDitch
Summer Dispersers: north out of the Gulf (Looking south) Large-billed Savannah Sparrow Yellow-footed Gull, Brown Pelican
Passage migrant songbirds Spring: Along eastern Gulf of California and directly through Salton Trough Fall: In hills west and east of Salton Trough Extensive use of native riparian and mesquite habitat
Vanishing (from CA) species Harris’ Hawk Elf Owl Fulvous Whistling-Duck
Vanishing (from CA) species • Elf Owl • Formerly common along LCR – now 1-5 pr. (if still breeds) • Most of habitat cleared for agriculture • Harris’ Hawk • Extirpated from Imperial Valley c. 1955, from LCR (CA) c. 1965 • Fulvous Whistling-Duck • Formerly (pre-1950) bred throughout southern Calif. wetlands • Fairly common at South End Salton Sea Impoundments until 1990s
Outlook for the Sea • “Do nothing” (Increased salinity/pollutants = fewer fish) • Declines in pelicans • Unhealthy birds? • Lower Colorado River continues to dry/degrade • “Save” the Sea w/o retaining some agriculture • No more Burrowing Owl, Sandhill Crane, curlews, etc. • Audubon is pushing for maximum restoration of entire LCR system, including the Salton Sea • Improvement to threatened ecosystems • Reflective of historic conditions • No “net loss” of birds • No increase of exotic vegetation
Thanks! Audubon California is the state office of the National Audubon Society. Formally established in 1996, it has its own Board of Directors and staff; manages >10,000 acres of centers and lands throughout the state; and raises 100% of its operating funds.