The Food of the Shag (Phalacrocorax aristotelis) in the Clyde Sea Area

1. The stomach contents of eighty-one shags (of which seventy-eight were obtained in the Firth of Clyde) were examined. 2. The diet consisted very largely of fish. 900 fish, belonging to at least twenty species, were recovered. Crustacea were of quite common occurrence in the stomachs of shags from certain areas. Large annelids were also found from time to time but were never common. Remains of a squid were recovered from one stomach. 3. Large numbers of fish otoliths occurred in the stomachs. These were counted and, whenever possible, identified. 4. The feeding habits of the shag were studied in nature. 5. The general conclusion is that the shag feeds mainly on fish of no commercial value and that the damage it does to food-fishes is quite negligible.