During a 13-yr period mean Great Blue Heron (Ardea herodias) clutch size at a central California colony ranged between 2.72 and 3.35 eggs, with an overall mean of 3.16. Mean Great Egret (Casmerodius albus) clutch size ranged from 2.70 to 3.07 eggs, with an overall mean of 2.87. Annual differences in clutch size were weakly significant in both species, and clutch size in both species declined slightly with relative as well as absolute time of breeding. The overall mean number of fledglings produced from heron nests was 1.45, with annual means ranging from 0.89 to 2.38.