It's not uncommon for female birds to lay eggs without a male bird being present. If you find an egg in your pet bird's cage, you're probably wondering how it happened, what to do with it, and whether or not it will hatch.
If you have a female bird, nature requires her to lay an egg now and then, but it doesn't necessarily mean you're going to see a baby bird or that the egg will hatch. Unless the hen has been exposed to a male bird before the egg or eggs were laid, the egg will not be fertile—in this case, most bird owners remove the egg from the cage and throw it away, and most of the time the hens go back to their normal routines.
There is no need for a male bird to be present for a female bird to produce an egg. Like the female human reproductive cycle that entails women must ovulate every 28 days, approximately, female birds have to release their eggs whether or not they're infertile. In fact, if breeding-age hens don't lay eggs regularly, they are at risk for egg binding, a potentially fatal health condition.
Egg binding is a medical condition that affects female birds that occurs when she in is unable to pass (or "lay") an egg that has formed internally. This condition is common and can lead to infection or internal organ damage for the bird if not addressed.
Depending on where the egg has lodged within the bird's body, it can sometimes be broken while still inside the hen. Sometimes massaging the hen's abdominal area can help the egg to pass safely, but other times you may need to seek a certified avian veterinarian to assist with dislodging the stuck egg.
If the egg is broken while still inside the hen, any shell fragments or residue must be removed to prevent infection, and her oviduct (the avian equivalent to the fallopian tube) should be cleaned by a professional
What to Do With Fertile Pet Eggs
If there is a chance that the egg your pet bird has laid is fertile and you want to raise the baby bird, you should candle the egg to see if it was indeed fertilized.
Candling is a process where a bright light is held behind an egg to illuminate its contents without cracking it open. A bird breeder can determine whether or not the egg is fertilized based on the color, shape, and opacity of the contents.
If you find the egg in your pet's cage was fertilized, you will need to either give it back to the mother for incubation or place it into an incubator if the hen will not sit on it. However, keep in mind that raising a baby bird from hatching is quite difficult and comes with a lot of extra care and attention.