Summary

Description

In late summer 1986, diets of nestling tufted puffins were studied at 18 breeding colonies between Prince William Sound and Unimak Pass as part of a continuing investigation into the commercial fish food dependencies of puffins in the northern Gulf of Alaska and eastern Aleutian Islands. Juvenile walleye pollock Theragra chalcogramma were found to be the main prey from the Sandman Reefs to Unimak Pass, but the species was a minor dietary component or absent from the diet east of there, where capelin and Pacific sand lance were the main prey. Two consecutive years 1985 and 1986 of data from the Semidi Islands show that pollock utilization dropped from 20 to 5 by weight, while that of sand lance increased from 50 to 80, thus underscoring the importance of continuing studies to learn annual variations in the diet.