Authors : Jyoti Ramteke
Page Nos : 188-196
Description :
Researchers developed special interest to study sexual dimorphism in Birds. Visibility of external gonads can determine the sex of Bird. The gonads, Testis in Males and Ovary in Female are different in morphology and locations are also different. The testis in Mammals is situated in the scrotum. However, in birds, the testes are found within the abdominal cavity, situated on either side of the backbone adjacent to the cranial pole of the left and right kidney. In female bird, the ovaries are present within the abdominal cavity. There are two ovaries in mammals, but in birds, there is only one functional ovary, which is always located on the left side, positioned similarly as the left testis. To locate the gonads of birds, one must therefore enter the abdominal cavity surgically. The male bird’s reproductive tract consists of the paired testes, epididymis, and ductus deferens. Accessory sex glands are absent in birds. The female bird’s reproductive tract consists of the left ovary and the left oviduct. The left and right ovary and oviduct develop embryonically as paired structures, but after hatching, the right ovary and oviduct degenerate.
