In avian species, including roosters, drakes, turkey toms, quail, guinea fowl and doves, some males possessed several sorts of accessory reproductive organs (ARO) and/or tissues, producing several kinds of accessory reproductive fluids (ARF), considerable amount of lymph-like fluids (LLF) and/or a tiny volume of foam or frothy fluids, at the moment of ejaculation. Only exception was the guinea fowl and dove, which produced neither LLF nor foam. A unique bird was the quail which produced a meringue-like foam (MLF). The LLF as well as foam were proven to play some important roles in improving activity and fertilizing ability of spermatozoa at the time of copulation and artificial insemination. In particular, the MLF of quail was also showen to be effective for disassembling clustered spermatozoa just after ejaculation when spermatozoa were mingled with the MLF. The ARFs were produced in several parts of the cloacal region of male birds, both ventral and dorsal regions. Special attention was also paid to the tissue at the vicinity of the papillae (TVP), which was observed in all of the male birds examined. This TVP always ejected very tiny amount of the LLF at any time of the day irrespective of copulation or ejaculation. On the one hand, of avian spermatozoa, quail and dove spermatozoa were typically unique in nature to form cluster in the vas deferens. However, only quail spermatozoa were not disassembled by any kind of semen extenders, and only the MLF and vaginal mucus could dissegarate clustered spermatozoa. On the contrary, clustered spermatozoa of the dove were disassembled by mixing with common semen diluents unlike clustered quail spermatozoa. These results indicated that almost each male bird possessed some AROs and/or tissues peculiar to the respective species, resulting in the production of the ARFs and/or foam which played some important roles for the enhancement of physiological function of spermatozoa. These all new findings were completely opposite against the firstly reported controversial papers and finally accepted as newly confirmed theory.