RED-PELAGED HARBOR SEALS OF THE SAN-FRANCISCO BAY-REGION

Harbor seals of San Francisco Bay, California, have a higher incidence of red pelage (range, 4-32% of the total count) than is observed alon g the outer eastern-Pacific coast or elsewhere in the world. Red pelag e was observed among all sex and age classes, except for pups. The pat tern of red coloration on the body varied; most seals had red hair ext ending from the head down to the shoulder. Elemental analyses of hair samples revealed that red coloration was from deposition of iron oxide precipitates on the hair shaft. We postulate that the particular cond itions within San Francisco Bay, including large areas of shallow wate r and strong summer winds with resuspension of sediments, bring suffic ient quantities of ferrous iron from the sediments into the water colu mn where it may serve as a principal source of the ferric oxide deposi ted on pelage of seals.