| Remarks |
A coastal species found <50 km offshore (Ref. 356). Nests in the interior of the North American continent and along the coast (Ref. 63805); on unvegetated, rocky outcroppings (Ref. 95237). Are common to abundant winter residents in freshwater and estuarine habitats in the state of Texas (Ref. 95239). Started to colonize the Great Lakes at the beginning of this century, on Lake Superior in 1913-20, and Lake Huron in 1932, returning each season and nesting from April until late September where they form dense colonies in trees or on the ground on small rocky islands. Lake Ontario supported 24% of the breeding population in 1991, and the largest colony of 5,428 nests on Little Galloo Island. Most begin to breed at 3 years of age (Ref. 95240). An opportunistic feeder (Ref. 95224). Exhibits plunge diving (Ref. 356). Generally preys on fish, often feeding in shallow waters (Ref. 95238). Feeds in river estuaries; on out-migrating juvenile salmonids (Oncorhynchus spp.) in the Columbia Basin (Ref. 95220); on alewife (Alosa pseudoharengus) and southeastern catfish (Ictalurus punctatus) (Ref. 95237); on crayfish (Orconectes sp.) (Ref. 95238); on shad (Dorosoma spp.) and sunfishes (Lepomis spp.) (Ref. 60211); on striped mullet (Mugil cephalus) and Gulf menhaden (Brevoortia patronus) in Lavaca Bay; striped mullet and Gulf toadfish (Opsanus beta) in upper Laguna Madre; typically targetting benthic fish or small schooling fishes and forage species (Ref. 95239). Average flight speed recorded at 61 km/h. (Ref. 95241). Preyed on by the bald eagle, Haliateeus leucocephalus (Ref. 95220). |