Wildlife success stories at the San Joaquin River National Wildlife Refuge (SJRNWR)
Aleutian Cackling Goose
The Aleutian was delisted from ESA in 2001 and returned to game status (i.e. hunted today). Presumed extinct until 1962, foxes released on Aleutian Islands by fur traders predated on eggs.
Wintering Aleutians were tracked to Stanislaus County in the 1980’s and the SJRNWR was established in 1987 to permanently protect the wintering grounds. At that time, approx. 300 individuals were estimated in existence.
Today, Aleutians return to the area every winter to fatten up on wetlands and harvested corn fields before returning north to breed.
Approx. 120,000 individuals are estimated in existence.
The warbler is a California Species of Concern, with a population declining since 1944. Once locally abundant in the Central Valley before dams, the warbler neared extinction in the Central Valley. Extensive surveys in 1998 and 1999 return no yellow warblers in the San Joaquin Valley.
At the SJRNWR (in and around lower 3 miles of Hospital Creek – west-side tributary to the San Joaquin River), one breeding pair was found in 2002, 26 in 2009, 25 in 2011 with 12 located in restored forests.
The SJRNWR is now considered the core of the recovering yellow warbler population in the San Joaquin Valley; Riparian habitat restoration will keep this declining species from being added to the endangered species list
Least Bell’s Vireo
The vireo is a State Endangered (1980) and a Federally Endangered (1986) species.
One of the most abundant birds in California prior to the 1930’s, it was last observed nesting in the San Joaquin Valley in 1919. It was reduced to 300 breeding pairs in 1986 throughout California. Subsequent habitat restoration has increased populations in southern California, but San Joaquin Valley populations remain dismal.
The vireo was successfully bred at SJRNWR in 2005 and 2006, and they nested in 3 year-old willows planted by River Partners, with mugwort, gumplant, and creeping wildrye nearby.
Riparian Brush Rabbit
The rabbit's a State Endangered (1994) and Federally Endangered (2000) species.
Once abundant in riverside forests between Stockton and Merced, is known from only two remnant populations today. The rabbit was suspected extinct after 1997 floods. A captive breeding and reintroduction program was initiated in 2001.
Threatened by flooding, the SJRNWR has restored high-ground habitat for rabbit that provides flood refuge and protection from predation. High-ground restoration began in 2006, and over 1,000 rabbits have been reintroduced here since 2002.
Following extensive floods in spring 2006, biologists did not detect the rabbit at SJRNWR until 18 months after flooding, despite relocating captive-bred rabbits. Since 2006, 32 mounds have been constructed and 8 miles of levee slopes have been vegetated. Following extensive floods in spring 2011, biologists detected riparian brush rabbits immediately after flooding without relocating captive-bred rabbits. The SJRNWR will provide the population recovery required to delist this species.
Valley Elderberry Longhorn Beetle
The beetle has been a Federally Threatened species since 1980.
This beetle is specific to one host plant: elderberry. Elderberry is a shrub that lives in riverside and streamside areas throughout the Central Valley. Beetle protection requires that elderberry shrubs are protected from destruction which directly conflicts with flood management requirements to control vegetation on levees and in floodways.
The SJRNWR project has planted over 40,000 elderberry shrubs in locations that do not conflict with flood management, providing long-term habitat sustainability for the beetle.
In October 2012, the USFWS proposed to remove this species from the endangered species list.