REPRODUCTION IN PEAFOWL
Most peahens will lay a few eggs when they are two years old. The peacocks are usually not fertile until their third year. Some cocks surprise us by producing fertile sperm at two, so use caution when allowing them in pens where you don't want them to be breeding.
It is thought that day length is a signal for breeding to start. This might coincide with more time for nutrition. I once used artificial lighting on chickens in the winter. The hens laid, but the roosters were not fertile. In peafowl, studies show that the testosterone is active sooner than the hen's ovaries. This sometimes results in an over- aggressive male injuring or killing his hen because she is not receptive to his advances. An increase in testosterone shows externally with displays of the tail, calling, and aggressiveness.
The drawing shows how an egg is formed. Only one egg at a time is in the oviduct. The journey starts when an ovum separates from the cluster (A.) and drops into the Funnel section. Fertilization (B) occurs in the Infundibulum where the sperm is stored in folds of tissue. Fertilization must occur before any white or shell is added to the egg. In (C) and (D), the outer yolk membranes are added. Chalazae are added at figure (E). These will anchor the yolk in the center of the egg.
Albumen and minerals are added while in the Magnum section (F). The whites contain lysozyne to act as a germicide protecting the yolk from outside bacteria. They also have hydrochloric acid to help to turn ingredients to blood. It converts protein to amino acids.
Inner and outer shell membranes are added in the Isthmus section. They are mostly together but separate to form the air sac. Calcification starts (F). Both the membranes and shell are porous. This allows humidity and air to pass in and out. Water is added and the egg comes into position in the Uterus (H). The kidneys are shown as (I). The large intestine is (J). The cloaca is (K) and (L) is the vent.
In the peacock, the testicles are located up next to the kidneys. They are shaped like a bean and are whitish yellow. They will enlarge and the color will change a little during breeding season. Anyone who has ever butchered chickens will remember seeing these in the older roosters. Sperm travels down the zigzag shaped tube called the ductus deferens. Peacocks have a non-erectile phallus and transmit the sperm in a cloaca to cloaca fashion. Contractions of muscles in the hen's vagina and uterus move the sperm up and the ovum down in the oviduct. The sperm has been known to last in the infundibulum of the hen for 30 to 40 days. This won't always be the case but it can happen. Breeding usually takes place shortly after an egg has been laid. Semen is not fertile between breeding seasons.
Most breeders gather the eggs to incubate either artificially
or under a foster mother. This encourages the peahen to lay more
eggs. If she is allowed to set on her own eggs, only 5 or 6 will
be laid. Ideally, the air temperature is lower than the hen's
(104) when the egg is laid and the air sac is formed as the membrane
contracts. Traditionally, the eggs are stored with the large
end up. This is supposed to keep the air sac where it belongs
and the yolk in good position. It seems to me that if the yolk
is stabilized with the chalazae and the air sac was established
when the egg was laid, this shouldn't matter. I'm not willing
to fool around with tradition and lose eggs by experimenting.
Keep track of the air sac size by candling during the incubation period. Too much humidity will leave a small air sac and the chick can't move to hatch. Too little humidity leaves a large air sac and the chick can't reach the shell to pip out. Air flow and water supply will adjust the humidity. Candling also tells you if an egg is fertile and how a chick is developing.
Keep the eggs cool, not cold. The manual for my old incubator recommended 56 degrees. I was able to maintain this with only a few eggs by using the butter container in the refrigerator. Now the eggs won't all fit there. I keep them cool and set them as soon as possible. Gather the eggs regularly. An egg left out in 100 degree weather for a couple of days will start incubating. When you then gather it and cool it, the embryo dies and won't be viable when you do set it. There are little blood lines, tiny eyes, and a little heart beating by the third day of incubation. A peafowl egg is supposed to take 28 days to incubate. A really freshly laid egg or an incubator which is slightly warmer than optimal may hatch early. Some eggs hatch a day or two late. I don't throw out any eggs until they are four days late. I just hate to give up on them.
Now you have chicks which, in two to three years, will start their own cycle of reproduction.