Male reproductive tract
The male reproductive system of birds is very elementary. Only the two paired testes with small epididymides and the ducti deferentes are present. There are no accessory glands. The copulatory organ is rudimentary (phallus non protrudens) except for Struthioniformes, Tinamidae and Anseriformes who have a phallus protrudens.
The left testis is bigger than the right one in most but not all birds. The pigeon for example is an exception on this. The testes are located intra-abdominal so there is no scrotum. The ducti deferentes open into the urodeum of the cloaca.