Transcript Birds of the Coastal Wetlands of Southern Sonora

Birds of the Coastal Wetlands
of Southern Sonora: Status
and Conservation
Osvel Hinojosa Huerta
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)
The Importance of Southern Sonora for Birds
• Stopover site for Neotropical
migratory landbirds
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
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
Threats to Birds in Southern Sonora
• Habitat loss and
degradation
• Mangrove areas
• Freshwater and
brackish marshes
• Riparian areas
• Disturbance of breeding
grounds
• Pollution
Threats to Birds in Southern Sonora
• Reduced avian productivity and survivorship
• Population declines
• Local extirpations
• Loss of biodiversity
Birds as Indicators of Environmental Health
3.5
Rails per station
3
Lineal (Rails per
station)
2.5
2
1.5
1
0.5
0
1999
2000
2001
2002
2003
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
Marshbirds of Southern Sonora
• 5 species
Ardeidae
American Bittern - Botaurus
lentiginosus
Least Bittern - Ixobrychus exilis
Marshbirds of Southern Sonora
Rallidae
Clapper Rail - Rallus longirostris
Virginia Rail - Rallus limicola
Sora - Porzana carolina
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)
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)
Protocol
• Variable distance point counts
• Survey stations 200 m apart
• Grouped in transects (5 stations)
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
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
Surveyed Wetlands in Southern Sonora
• Estero Santa Cruz
• Punta Santa Rosa
• El Soldado
• Miramar
• Tobari System
• Yavaros
• Huatabampo
• Agiabampo
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
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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Ag
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va
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Dr
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am
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ab
To
ba
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m
ar
Dr
ai
M
ira
Hu
at
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Cr
uz
Ro
sa
So
ld
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Sa
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Sa
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Marshbird Abundance
40
35
CLRA
LEBI
30
VIRA
AMBI
25
20
15
10
5
0
Marshbird Density
2.5000
CLRA/station
2.0000
Mbirds/station
1.5000
1.0000
0.5000
0.0000
Kino
Guaymas
Dren Tobari
Tobari
Dren
Huatabampo
Yavaros
Agiabampo
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
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
Next Steps…
• Outreach and Environmental Education
• Support decision making and management
• Conservation!