美洲鳄是机会主义的杂食性肉食动物,其觅食偏好会随着成熟而改变。幼鳄主要以小型水生无脊椎动物为食,包括蓝蟹、招潮蟹、淡水虾和小型河口硬骨鱼,如鱂鱼和幼笛鲷。随着它们成长为大型成年鳄鱼,其食谱显著扩大,包括更大的海洋鱼类,如大海鲢、狼鲈、石斑鱼和小型魟鱼,以及海龟、水鸟(如苍鹭和鹈鹕)和沿海哺乳动物,如浣熊和野猪。
Hunting occurs predominantly at dusk and throughout the night. Utilising sensitive pressure-detecting integumentary sense organs distributed across their jaws, they detect minuscule vibrations in murky water. They employ a classic ambush technique, remaining submerged with only their nostrils, eyes, and ear slits breaking the surface, before lunging forward with explosive speed to snap their prey, often drowning larger animals before swallowing them whole.