Venturing into White-faced Ibis Territory

By Dale Garrison and Carley Sweet

A swirl of graceful birds with white faces circles high above. The brilliant cinnamon bodies and flash of green and purple sheen on the wings are unmistakable:

White-faced ibis have arrived in record numbers at the Kern National Wildlife Refuge.

More than 6,000 ibis have taken up spring residence at the refuge this year. Compared to the 150 ibis counted on the refuge 10 years ago, the birds have made quite a comeback. The Kern refuge now serves as home to the largest population of breeding ibis in the San Joaquin Valley.

Abundant numbers of juvenile ibis have also been spotted this year. A trek through the waist-high water into the dense bunches of cattail and tules in early April uncovers hundreds of bowl-shaped nests made with reeds, holding three or four babies each. The shaky youngsters can be seen taking flight from their roosting sites to try out their new wings, or taking a stab at gathering a wetland meal by prodding and pecking for small insects, crustaceans, and earthworms in the mud. Their black and white striped bills, grayish bodies, and green iridescence make them distinguishable from mom and dad.

The adults are interspersed with the young ones, enjoying all the benefits the increase in water has supplied to their wetlands. Their curious red eye is keen in spotting skunk and coyote -- prime predators in the wetland community. Ibis answer their hungry stomachs by using their long, downward curved bill as a probing device to search out delicacies of critters found under the water. These colonial birds flourish in the right environment -- in ponds dominated by extensive stands of tules and cattails, maintained with fresh, good-quality water 1 to 2 feet deep.

Up until 1992, habitat managers at Kern National Wildlife Refuge depended upon unreliable water sources to flood their wetland ponds in the fall, or on wells or the pure luck of sufficient rainfall to sustain the wintering waterfowl habitat until spring. Given these shaky fall and winter water supplies, Kern NWR often was left high and dry from April to September.

The passage of the Central Valley Improvement Act of 1992 (CVPIA) changed the unsettled water situation. CVPIA brought with it mandates for reliable, year-round water supplies for Kern NWR, as well as 12 other refuges within the Central Valley. By the second year of the Act, with water vegetation becoming dense and water supplies increasing, the ibis count at Kern topped 1,000 for the first time.

By 1998, more than 4,000 birds arrived at the refuge, and this year's arrivals are the highest ever.

Before CVPIA, ibis numbers were limited at Kern NWR to a few dozen sightings in any given year. Habitat conversion and the deadly impacts left over by decades of agricultural use of DDT had taken its toll. The ban of DDT in 1970 certainly has helped recovery of the species but the toxin's residual effects continued for many years afterward.

The response of the white-faced ibis to this new water source and habitat has been nothing short of remarkable. With a continued reliable water source for its wetlands breeding habitat, the ibis' future in the lower San Joaquin Valley looks promising.

Dale Garrison is a Refuge Program Specialist and Carley Sweet is an Information and Education Assistant. Both work in the Sacramento Fish and Wildlife Office.

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Young White-faced Ibis chick

Group of adult Ibis feeding at Kern NWR

Adult White-faced Ibis on nest

Adult Ibis in flight

Adult White-faced Ibis at Kern NWR

Juvenile White-faced Ibis

Adult White-faced Ibis in flight