The White-faced Ibis (Plegadis chihi) has been classified as a Bird Species of Special Concern in California (Remsen 1978, S. Laymon pers. comm.) and a potential candidate for federal threatened or endangered status (USFWS 1991, Trapp 1995) because of population declines in the western United States, particularly in the 1960s and 1970s (USFWS 1985, Ryder and Manry 1994). Although the breeding status of the ibis in this region has been reviewed (Ryder 1967, USFWS 1985, Ryder and Manry 1994), little has been published on its abundance and distribution in winter. Here we summarize data on the winter distribution, abundance, and habitat use of the White-faced Ibis in California during the last half century. We also estimate the current winter population size and review historical population trends.