Feeding preference and foraging impact of wintering coots on submerged aquatic vegetation

摘要: Abstract While it has been well established that waterbirds can consume substantial amounts of submerged aquatic vegetation (SAV) on their wintering grounds, relatively little is known about effects SAV in the northern Gulf Mexico (nGOM). We measured impact American coot (Fulica Americana) foraging native wild celery (Vallisneria americana) and exotic Eurasian water milfoil (Myriophyllum spicatum) using caging experiments at two locations upper Mobile Bay during winter 2013–2014. also determined feeding preferences tethering experiments, monitored location coots behavior individual birds. Coots were significantly more abundant over watermilfoil than celery. Caging usually showed higher biomasses exclusion cages, suggested a larger Video recordings confirmed responsible for losses detected with both dietary analyses supported experimental results highlighted role coot's diet (86.9 ± 8.9% stomach contents). Tethering preference milfoil, which likely explained by nutritional quality (19.26 ± 1.21 C:N ratio) compared to (25.01 ± 2.45 ratio). Overall, our are similar those several prior seagrass herbivory studies showing herbivores do not always feed preferred food, presumably because other factors, such as proximity refuges from predators or competition food resources, overriding importance.