Caiques lay white eggs like all other parrots. Their size can vary from 3.1 to 3.3 cm long and from 2.2 to 2.6 wide (1.25 to 1.31 inches x 0.87 to 1.03 inches). The size appears to be a function the size of the female, its health and the number of eggs in the clutch. I have noticed that the last egg in a clutch of four is almost always smaller than the earlier ones. There does not appear to be any correlation of egg size and the final bird size. Nearly every female will lay eggs at one point in its life whether or not it has a mate. Of course, birds without mates lay infertile eggs. Just before a hen lays an egg, its behavior will change. I can tell when one of my non-tame pairs is coming into season by when the hen refuses to accept a pecan treat from my hand. Pets that are about to lay will want to stay closer to their box and work the wood chip filling. They will push most of the filling out of a shallow box and you will have to keep refilling to prevent the egg from rolling around on the hard floor of the box. If the female is an unmated pet, it will want to be with you more at first, but later it will want to be left alone. When it becomes gravid, the bird will develop a noticeably enlarged abdomen. Some females become aggressive, especially the first time, but most pet birds will allow you to look in on them while they are incubating their eggs. A pet bird may even allow you to pick her up and inspect her eggs while she is in the nest. Another sign that an egg is imminent is when the female starts to chew on its cuttlebone or mineral block. Pet females allowed out of their cages may chew your plaster walls. So keep an eye on them when this occurs. When I become aware they are in season, I provide them with more protein and calcium. Some people provide them with "egg food." This is usually cooked chicken eggs or eggs baked into corn cakes egg shells and all. I usually just provide them with whatever meat I am eating that evening, a little cooked beef, chicken, fish or pork. I am also more assiduous about providing them their 1/2-inch cube of cheese. If its a pair, you must give meat to both the male and female otherwise the male will take it away from the female.

If an egg is fertile, and the incubation goes well, a chick will hatch in 25 to 29 days. The length of the incubation depends on the temperature of the surroundings and how tightly the hen sits. They require longer when it is cool. You can determine if the eggs are fertile by candling. If you have good equipment, you can follow the development of chick in the shell. Eventually, they will become opaque due to the development of the chick. If there is no noticeable increase in the opacity after a week, the eggs are usually infertile. This will be the case if the bird does not have a mate. I leave all infertile eggs with the hen for the length of time normally required for them to hatch. At that time, I remove them. After checking its box a few times and tossing out much of its bedding, most hand tame single females revert to their original behavior as though they had never laid. Breeding pairs of caiques may lay three to four clutches a year. However, none of my single pet females has ever laid more than one clutch in a year.

A website showing the candling of parrot eggs may be found at the the True Companion Aviary website. The Shadypines website has a sequence of pictures of a yellow-thighed caique hatching. For more about parrot eggs and hatching them there is additional information in the Hagen Avicultural Institute website.