Stanislaus River Basin and Calaveras River Water Use Program
Threatened and Endangered Species Report - March 1995
Bay Delta and Special Water Projects Division, CA Dept of Fish and Game
White-faced Ibis
Plegadis chihi
California Department of Fish and Game "Species of Special Concern"
Life History
The white-faced ibis inhabits fresh emergent wetlands. It is about 23 inches long with a
long bill that curves slightly downward. It has red eyes and legs, a reddish bill, and a border
of white feathers that is just behind the facial skin and extends behind the eye all the way
around the face.
The ibis prefers to feed in fresh emergent wetlands, and shallow lacustrine waters. The
muddy grounds of wet meadows, irrigated or flooded pastures, and croplands where the long
bill enables it to probe deep into the mud. The ibis diet consists of earthworms, insects,
crustaceans, amphibians, small fishes, and miscellaneous invertebrates.
Extensive marshes are required for nesting. Here nests are constructed of dead cattails
or tules and built either in tall marsh plants or on mounds of vegetation. The ibis can be a
colonial nester and those nests within a colony were found to be about seven feet apart. A
requirement for nesting is the proximity of suitable foraging areas. Clutch sizes average three
to five eggs which are incubated for about 21 days. The young are fed in or near the nest for
about five weeks.
Findings and Conclusions
Because of the loss of marshes throughout California, regular breeding in the state has
stopped. There have been reports of isolated nesting, but regular nesting has been
inconsistent. Elsewhere in the range pesticides have also been found to have caused a decline
in numbers.
The white-faced ibis is considered a rare visitor to the Central Valley. It may be found
during the winter when it is migrating through the valley and transients may also be present at
other times of the year foraging and flying throughout the day. No ibis was observed or
reported along the Stanislaus River and it is doubtful that projects along the river would have
any impact on the species.
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