初中《生物》对鸟类的尿及其排泄作了如下介绍：“由于鸟类的尿总是和粪便一起排出体外，而尿液又浓又少，因此排出的尿液就显得不那么明显了”。这种解释会被误认为鸟类的尿液以水样的形式混在粪便里，由于较少，所以不易看见。其实根据高等教育出版社所编的（动物学）等资料 The junior high school “Biology” described the urine and its excretion of birds as follows: “Because the urine of birds is always excreted with excrement and the urine is thick and small, the discharged urine is not so obvious. ". This explanation can be mistaken for the fact that the urine of the bird is mixed in the form of a water sample in the faeces, which is less visible because it is less. In fact, according to information compiled by the Higher Education Press (zoology)