要论忠诚，美洲鸵肯定不是，因为它们没有固定的配偶。正因如此，雄鸟要独自承担起孵卵、喂食、照顾和保护后代的重任。

 Rheas are large South American birds similar to ostriches . Father rhea takes sole care of his young. From eggs to chicks, he feeds, defends, and protects them until they are old enough to survive on their own.