180 likes | 465 Views
Birds and the Salton Sea. Habitat diversity in the Lower Colorado River Valley (
E N D
1. 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
3. 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
4. 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
5. The Salton Sea avifauna Lower Colorado River (“LCR”) Endemics
“Last Stand” breeders/winterers
Winter congregants
Summer dispersers
Passage migrants
Vanishing (vanished?) nesters
6. 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
7. “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
8. 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
9. Winter congregants… (agricultural)
10. Winter congregants… (the Salton Sea itself)
11. Winter congregants… (the Salton Sea itself)
12. And lots in between…
13. Summer Dispersers: north out of the Gulf
14. Passage migrant songbirds
15. Vanishing (from CA) species
16. Vanishing (from CA) species
17. 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
18. Thanks!