Diapositiva 1

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Birds of the Coastal Wetlands of Southern Sonora
Status and Conservation
Osvel Hinojosa Huerta
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The Importance of Southern Sonora for Birds

• Over 260 species
• Critical wintering and stopover site in the
  Pacific Flyway
• Waterfowl (120,000 25 species)
• Shorebirds (90,000 28 species)

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The Importance of Southern Sonora for Birds

• Stopover site for Neotropical migratory landbirds

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The Importance of Southern Sonora for Birds

• Breeding waterbirds
• Marshbirds
• Colonial waterbirds
• Protected Species
• 19 species
• Least Tern
• Clapper Rail
• Piping Plover
• Brant
• Least Grebe

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The Importance of Southern Sonora for Birds

• 7 AICAs (Important Bird Areas)
• Important site for North American Wetlands
  Conservation Council
• Priority Site for Conservation of Biodiversity
  in the Gulf of California

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Threats to Birds in Southern Sonora

• Habitat loss and degradation
• Mangrove areas
• Freshwater and brackish marshes
• Riparian areas
• Disturbance of breeding grounds
• Pollution

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Threats to Birds in Southern Sonora

• Reduced avian productivity and survivorship
• Population declines
• Local extirpations
• Loss of biodiversity

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Birds as Indicators of Environmental Health
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Marshbirds of Southern Sonora

• Breed in areas with emergent vegetation or
  mangroves
• Strongest dependence upon wetland ecosystems
• Sharp population declines in North America
  habitat loss
• More drastic in the Sonoran Desert Ecoregion

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Marshbirds of Southern Sonora

• 5 species
• Ardeidae
• American Bittern - Botaurus lentiginosus
• Least Bittern - Ixobrychus exilis

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Marshbirds of Southern Sonora
Rallidae Clapper Rail - Rallus
longirostris Virginia Rail - Rallus
limicola Sora - Porzana carolina
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Marshbirds of Southern Sonora

• Determine the status of marshbirds in SS and set
  a baseline for a long-term monitoring program
• Part of a regional effort to determine the
  relative abundance and distribution of marshbirds
  in Northwestern Mexico
• Linked to a continental effort to estimate
  population trends of marshbirds in NA (USGS
  USFWS)

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Protocol

• Standardized Protocol for Monitoring Marshbirds
  in North America (Conway 2002)
• Based on call-response surveys 30 s of
  vocalizations of each species, followed by 30 s
  of silence
• Counts during breeding season, when vocalization
  rate increases (May-June)

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Protocol

• Variable distance point counts
• Survey stations 200 m apart
• Grouped in transects (5 stations)

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Protocol

• Counting the number of individuals of each
  species responding to the tapes, along with
  distance estimation
• Habitat measurements at each station cover
  classes, veg height, salinity, and water depth
• Support with GIS and satellite images for change
  analysis and density estimates

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Surveyed Wetlands
Sonora Delta del Río Colorado Estero Santa Rosa,
Estero del Soldado, Sur de Sonora Baja
California Punta Banda, Río San Telmo, Bahía San
Quintín, El Rosario, Laguna Guerrero Negro
Baja California Sur Laguna Ojo de Liebre,
Laguna San Ignacio, Bahía Magdalena, Ensenada La
Paz, San José del Cabo Sinaloa Ensenada
Pabellones y Bahía Santa María
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Surveyed Wetlands in Southern Sonora

• Estero Santa Cruz
• Punta Santa Rosa
• El Soldado
• Miramar
• Tobari System
• Yavaros
• Huatabampo
• Agiabampo

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Total Survey Effort
Wetland Survey Points
Punta Santa Rosa 8
Estero Santa Cruz 13
Estero del Soldado 10
Estero Miramar 10
Dren Tobari 10
Bahia Tobari 25
Dren Huatabampo 6
Yavaros 15
Agiabampo 8
Total 105
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Preliminary Results

• 124 individuals from 4 species
• Clapper Rails are common in mangrove areas
• Distribution is patchy some mangrove areas
  without CLRAs
• Other marshbirds are very scarce

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Marshbird Abundance
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Marshbird Density
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Preliminary Results
Region birds/station
Southern Sonora 1.1810
Baja California Sur (MB, LP, GN) 0.9971
Santa Maria, Sinaloa 3.6330
Colorado River Delta 4.0812
Baja California (Pacific) 1.9542
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Next Steps

• Data analysis and reporting
• Develop and implement monitoring plan
• Regional Conservation Plan for Marshbirds
• Include other guilds and species to assess the
  status of the wetlands of Southern Sonora

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Next Steps

• Outreach and Environmental Education
• Support decision making and management
• Conservation!