Chronic egg laying occurs when a female bird lays more than the normal number of eggs or, more commonly, lays repeated clutches of eggs, especially in the absence of a mate.
"The persistent laying of eggs may lead to malnutrition"
The persistent laying of eggs may lead to malnutrition induced by the chronic depletion of calcium from the body for the production of the egg shells. In time, this excessive production may result in egg binding (See handout titled Egg Binding).
Are certain birds prone to becoming chronic layers?
Cockatiels, lovebirds, and budgerigars (budgies) are most likely to become chronic egg laying birds. It is also noted in Amazon parrots and Macaws, but any species of bird can develop the problem. Hand-raised birds that use their owners as mate substitutes will develop the problem more frequently than wild caught birds.
What causes chronic egg laying?
"Removing eggs that are already laid also seems to induce birds to lay even more eggs."
We do not really know the answer to that. However, something stimulates these birds to lay more eggs than normal, or more frequently than normal. A lack of hormonal balance that tells most birds to stop laying eggs likely exists in chronic egg laying birds. Removing eggs that are already laid also seems to induce birds to lay even more eggs.
Are there any health problems associated with chronic egg laying?
Many birds with chronic egg laying are eating a poor diet consisting mainly of seeds, so are usually already malnourished. Egg laying will use up a great deal of calcium. For normal birds this is not a problem as the body can compensate; however, for birds eating a calcium deficient diet (all seeds), hypocalcemia may result. This can cause egg binding, seizures, or death.
Are there any other problems associated with chronic egg laying?
Birds are often less friendly when they are under the powerful influence of reproductive hormones, and may be aggressive and vocal as they protect their clutch. They may 'display' and become very territorial.
What are the recommended treatments for chronic egg laying?
No single treatment has been shown to be effective. Some of the things that have been suggested to control this behavior include:
- First, make sure your bird is eating a proper diet so she will not to become malnourished. A calcium supplement may be appropriate at these times.
- Decrease the number of hours of daylight exposure, which may influence the stimulus to lay eggs.
- Move the bird's cage to a different location in the house to increase her feelings of comfort and security.
- Minimize handling your bird, especially stroking or petting her. It may be necessary to decrease the amount of time spent with her until egg laying is reduced or ceases.
- If you have been removing eggs as they are laid, stop doing this as it may decrease the stimulus to complete the clutch by laying more eggs. Leaving the bird to sit on her eggs for the duration of a normal hatch (around 21-28 days) will allow her to become broody (do mother bird stuff), rest, and recuperate or catch up a little from the hard work and stresses of egg laying. At the end of this time period the eggs may be removed one every 1-2 days. However, some birds will start the process over again.
If these steps don't work, are there any medical treatments?
Medical therapy may be needed in some cases. Hormone injections can stop egg laying, although they are not without side effects. It is also possible to perform a hysterectomy in cases that can't be controlled any other way. Both of these options should be discussed thoroughly with your veterinarian.