Abstract
Analyses of petrel stomach oils have revealed their composition to be very variable. In early studies, wax esters in these oils attracted much attention. Recently wax esters were discovered to be major reserve lipids in deeper-living marine animals (squid) and such animals were the main prey of several petrels. Stomach oil is probably a dietary product and a probable mechanism for its formation is known. Wax esters seem to become more concentrated in this oil than in lipids of the food consumed, possibly because of preferential digestion of triglycerides.