Why do cockatiels and some of the other smaller species of pet birds produce eggs when there is no male present?
Over the last few years, female cockatiels and other small pet bird species have accidentally been selectively bred for their ability to lay eggs without a mate present. We need to look back a few generations to find the source of the problem. Veterinarians, breeders and hobbyists have, in error, advised owners that a mate should be provided for these egg-laying pets. This is, in fact, the last thing that you want to do. Laying too many eggs can be a health hazard for a hen. Breeding her will increase the number of birds with this problem in the future.
The poultry industry has used this selective breeding technique in a positive way to significantly increase egg production in chickens. The original chicken was a small bird that laid an average of seven eggs each year. Today, with selective breeding and proper nutrition, the average chicken produces 252 eggs per year.
The hen that lays the most eggs and the most clutches of eggs in her life, produces the most babies. Super-producing hens are showing up at an increasing rate and developing into a major health problem for small companion birds. Professional and hobby breeders alike, utilize these abnormal hens to produce as many babies as possible for the pet trade.
Some of the female babies produced by these prolific hens will also have the ability to produce many eggs. If these females end up in a breeding situation, they will also produce a lot of babies and end up passing this trait on to more female babies. Over the last 20 years, some of these very prolific hens have caused these super-ovulating genes to be fixed into a significant percentage of the cockatiel and other small bird populations.
This situation is not limited to small birds. Because of the older age at which many of the larger parrots start to produce, they have not had as many generations of production. Smaller birds can begin reproducing at one year old while many of the larger parrots take five to ten years. This problem has developed in about 15 generations for the smaller birds. In about another 25 years, it will likely be as common in the larger parrots.
Problems that can arise A few of the birds that develop this problem will not suffer any undesirable effects. Unfortunately, this is not the situation for most of these birds. Many undesirable problems and situations can develop when a bird becomes a chronic egg layer. These problems include but are not limited to: