Diet of double-crested cormorants wintering in Texas

The diets of 420 Double-crested Cormorants (Phalacrocorax auritus) were studied during November 1986-March 1987 on eight public reservoirs in Texas. Prey included 29 fish species and the mean live weight of fish per bird was 122 g. Fishes a??415 mm long were ingested, but those a??125 mm accounted for 90% of cormorant food contents by number. Shad (Dorosoma spp.) and sunfishes (Lepomis spp.) accounted for 90% of the total food items by number. Consumption of fishes (percent by weight) was different for male vs. female and adult vs. juvenile cormorants. Total consumption of fish by weight was consistent throughout the period; however, fewer but much larger fish were consumed after 15 February. Cormorants ate fishes that were most abundant in reservoirs. Sport fishes made up a substantial portion of cormorant food by weight, but not by number on some reservoirs. Cormorants ate very few large sport fish, however.