Daily time budgets and activity patterns of sea otters (Enhydra lutris) were determined by scan sampling at 4 study areas in central California. Diet was determined by direct observation of foraging animals. Average time invested in foraging ranged from 11 to 71% among viewing areas (1-2 km of coastline) and from 21 to 28% among study areas (8-10 km of coastline). Foraging time budgets were unrelated to season or the length of time that an area had been inhabited by otters. The diet of sea otters in California consisted almost entirely of marine invertebrates. These patterns were consistent with our review of other information on sea otter activity and diet in California. Diurnal foraging patterns were distinctly crepuscular at all sites and times sampled but one. Afternoon peaks in foraging activity were greater than morning peaks. Time budgets and diets were similar to those of sea otter populations in Alaska and the Soviet Union that were known to be below equilibrium density, thus suggesting that the presently curtailed growth of the California sea otter population is not due to food limitation.
