How do chickens mate?

Here ya go, just found this:

The Sex Lives of Birds

Mr. Bird has found his season’s love, and she loves him back. What causes these birds to form these bonds in the spring and summer, not when it is cold and snowy, nor while they are migrating?

Hormones from the pituitary gland are the answer. During breeding season in response to the hormones, the male’s testes become several hundred times larger than normal to produce sperm, with the left testis usually larger.

The female bird’s ovaries also enlarge during breeding season to produce the ovum. Female birds usually only have one functional ovary, the left one.

In birds, an ovum is fertilized in the female bird’s oviduct by a sperm cell from the male bird. Once fertilized, the ovum becomes the nucleus of the egg. The egg, that has its own food source, the yolk, will be laid by the female into her nest, incubated, and then the baby bird will hatch.

But how does the sperm from the male bird get into the female? How can they have intercourse without any external male organs, such as a penis?

The male’s sperm, produced in the testes, passes to the *cloaca where it is stored until copulation (act of sex). The female also has a cloaca that leads from the ovaries. The female bird unfans her tail, moves it to one side while the male climbs up onto her back or gets close to her.

Their cloacas are pressed together and the sperm moves from the male to the female. This act is called a cloacal kiss. Click here for a diagram of the male and female bird sex (reproductive) organs.

The sperm is stored by the female for at least a week, in some species over a hundred days. Then as each ovum from the ovary moves into the oviduct, it gets fertilized with the stored sperm, producing a clutch of many eggs, all with the sperm from that one cloacal kiss.

There are a few species of birds where the males do possess a retractable penis that can be pulled back into the bird. These birds include ostriches, cassowaries, kiwis, swans, geese, and ducks. Since waterfowl sometimes make love while in the lake or pond, the penis helps ensure that the sperm is not washed away by the water.

Sperm can be transferred from male cloaca to the female in a blink of an eye - less than a second. Some birds seem to want to linger longer though, sometimes having sex for more than an hour!

And, although it is not necessary to copulate frequently since the sperm is stored within the female, remember those hormones are still making the birds excited. Many pairs of birds will mate numerous times within a few days.

*In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, urinary, and (usually) genital tracts of certain animal species.