Imperial National Wildlife Refuge IBA ☼ ◊

Global IBA for Black Rail and Continental IBA for Yuma Clapper Rail

Site Steward: Yuma Audubon Society

Size: 49.3 square miles, 31,558 acres

Identified: 06/2008

Visiting the IBA: From Yuma: Travel north on Highway 95. Near Milepost 47 turn left onto Martinez Lake Road. Follow Martinez Lake Road west for approximately 10 miles. Turn right onto Red Cloud Mine Road and follow signs directing you to the Visitor Center.

Site Description: A 30-mile reach of the Colorado River bisects the refuge. Over 14,000 acres of the Refuge’s desert upland habitats are designated Wilderness area. Major resource initiatives on the refuge include restoration of native riparian habitats and wetlands to benefit migratory birds and other riparian-obligate species.

Birds: Spring and Fall offer the greatest variety of birds and the best birding opportunities. 275 species have been observed on the refuge. Also, the refuge is important as a wintering area for Canada geese and many species of ducks. Part of this IBA is within the Yuma Christmas Bird Count circle. Species of special conservation status and interest that use the habitats within this IBA include:

Year-round: Ladder-backed & Gila Woodpeckers, Phainopepla, Verdin, Crissal Thrasher, Abert’s Towhee.

California Black Rail by Julio Mulero

Breeding: Yuma Clapper Rail, California Black Rail, Sora, Least Bittern, Pied-billed Grebe, Clark’s & Western Grebes, Common Poorwill, Yellow-billed Cuckoo, Bell’s Vireo, Lucy’s Warbler (early spring), Yellow Warbler, Summer Tanager.

Migration: Sandhill Crane (rare, migration & winter), Willow Flycatcher.

Winter: Canada and White-fronted Geese, Tundra Swan (rare, winter), Peregrine & Prairie Falcons, Bald Eagle, Sage Sparrow.

Conservation Concerns: Historic loss of cottonwood and willow and marshlands habitats from the impacts of dikes, diversion canals and dams on natural hydrologic regime. Strategies: The Lower Colorado River Multi-Species Conservation Plan is implementing riparian forest restoration projects.

Maps of this Important Bird Area:

Imperial National Wildlife Refuge IBA

Imperial National Wildlife Refuge IBA – zoomed out

State of the IBAs 2014 Baseline – More Technical info about the status of this Important Bird Area

National Audubon Profile Page for Imperial National Wildlife Refuge IBA

Complete eBird.org Checklist of birds Reported for Imperial National Wildlife Refuge IBA

For an interactive map and habitat and land ownership analysis of this IBA visit the National Audubon IBA Map and select “Arizona” and then the name of this Important Bird Area. To access analysis graphs, click on the map boundary of the IBA.

Location: 32° 53’N, -114° 27’W

County: Yuma

Site Status: Identified 06/2008

Ownership: Federal and State

Area: 49.3 square miles, 31,558 acres

Criteria: A1 Global -Species of Conservation Concern – Black Rail (12 breeding pair – 2006)

B1 Continental – Species of Conservation Concern – Yuma Clapper Rail (43 breeding pair – 2009)

D1 – Site Important to Special Status Avian Species – Federally listed Yuma Clapper Rail and SGCN Black Rail

D3 – Rare, Unique, or Exceptional Representative Habitat/Ecological Community –Marsh and River Slough

D4i – Significant Concentrations of Birds, >1% State population: D4ii Waterfowl (2000+)

Site Description: The Imperial NWR lies within the Lower Colorado Subdivision of the Sonoran Desert, a region characterized by a scarcity of precipitation and high summer temperatures. A 30-mile reach of the Colorado River bisects the refuge. Over 14,000 acres of the Refuge’s desert upland habitats are designated Wilderness. Major resource initiatives on the refuge currently include restoration of native riparian habitats to benefit several declining populations of neotropical migratory birds and other riparian-obligate species, Colorado River native fish management, wetland restoration and moist soil management to benefit migratory bird species, development of baseline biological databases, and environmental education and public outreach.

Ornithological Summary:

Clapper Rail by Matt Tillett

Three Marshbird surveys have been established in 2008 as a part of the Multi-species Conservation Plan. A rapid survey is being conducted at the area which will be planted with cottonwood-willow land cover type, and adjacent habitat. The area which was planted was bare ground in the summer of 2007 and no birds were present, but the adjacent cottonwood nursery and a thin strip cottonwoods and willows planted on the west side were also surveyed as these areas will serve as sources for bird populations that will colonize the cottonwood-willow site, when planted.  In these areas four LCR MSCP listed bird species were detected.  These species were the: summer tanager (1 detected), yellow-billed cuckoo (Coccyzus americanus) (1 detected), Gila woodpecker (Melanerpes uropygialis) (1 detected), and yellow warbler (1 detected). (MSCP unpub. 2008 progress report-Chris Dodge).

Conservation Issues: Historic loss of cottonwood and willow and marshlands habitats from the impacts of dikes, diversion canals and dams on natural hydrologic regime. These losses are currently being mitigated through the LCR-MSCP. The Lower Colorado River Multi-Species Conservation Plan is implementing riparian forest restoration projects.