Tomales Bay, on the Marin County coast, is one of California's largest and least disturbed estuaries, yet little has been published on the status of its waterbirds or their vulnerability to environmental threats. Shuford et al. (1989) reported the results of waterbird censuses of up to 10 consecutive years in the adjacent Point Reyes area between 1965 and 1982 but provided limited information on waterbird use of Tomales Bay.

In November 1989, Audubon Canyon Ranch (ACR) began an ongoing program to monitor seasonal populations of shorebirds (Scolopacidae and Charadriidae) on Tomales Bay. Three baywide counts, treated as replicates, are completed within each Nov.-Dec. and Jan.-Feb. census period, to estimate early winter and late winter population levels, respectively. An additional baywide count is conducted each August and April in an attempt to record peak numbers of fall and spring migrants.

Shorebird monitoring program on Tomales Bay, California

Audubon Canyon Ranch has monitored shorebird populations (Scolopacidae and Charadriidae) on Tomales Bay since 1988. I examined ten years of shorebird monitoring data for population trends and shifts in local foraging distributions, and related these patterns to flock movements, populations, and variations in weather. We conducted eight baywide counts of shorebirds each year and estimated early winter and late winter population levels.

Effects of weather and feeding regime on habitat use and body mass regulation in wintering shorebirds on Tomales Bay, California

Audubon Canyon Ranch has monitored shorebird populations (Scolopacidae and Charadriidae) on Tomales Bay since 1988. I examined ten years of shorebird monitoring data for population trends and shifts in local foraging distributions, and related these patterns to flock movements, populations, and variations in weather. We conducted eight baywide counts of shorebirds each year and estimated early winter and late winter population levels.