Uncontrollable egg-laying in cockatiels can be frustrating for companion bird owners, and often life threatening for cockatiel hens. The over-production of eggs or an irregular pattern of laying eggs can rob a hen of the necessary calcium needed to form her eggs.

    Examples of abnormal egg-laying include laying an egg daily or every few days rather than every other day; laying a round of eggs on the heels of an earlier clutch; or continuously laying eggs nonstop for weeks. If allowed to continue, eventually calcium will be drawn from the hen's bones leaving them vulnerable to fractures, serious osteoporosis, the dangers of soft-shelled eggs, egg-binding, and egg peritonitis, all of which can be fatal.

    Once eggs are laid, do not remove them. Always allow the hen to incubate should she choose to, otherwise she will merely lay another round to immediately replace the clutch she lost. This effort will only tax her resources and rob her calcium supply further.

    Cockatiels are stimulated to reproduce when six necessary conditions are present in their environment: ideal temperature, proper humidity, increased photo-light period, appropriate seeding grasses or soft foods for feeding young, a suitable nesting site, and an acceptable suitable mate. To stop the production of eggs, first try to reverse some or all of the above conditions.

    Ideal temperatures for cockatiels vary. Although primarily a desert bird living in arid regions of the interior of Australia, the domesticated cockatiel can adapt to most any temperature comfortable for humans. Breeders who house their collections outdoors usually breed only during the warmer months, avoiding the colder chill of winter that can cause egg-binding. If birds are weathered outdoors, a heat source and some shelter is normally provided. Breeders who house their cockatiels indoors usually keep them at room temperature within 68-72 degrees Fahrenheit. Many breeders keep their flocks at slightly cooler temperatures to keep them hardy. It is not recommended to vary from the normal comfort zone when deterring your cockatiel from laying eggs, as she will need all the warmth and nurturing you can provide for her at this stressful time.

    Humidity is not as an important factor. Humidity primarily affects the ability of the embryo to turn in its shell, and often times cockatiels that over produce eggs are kept as companion birds and therefore their eggs do not contain fertile embryos. Constant baths may be somewhat stimulating, so eliminate spray baths until egg-laying events are over.

    The photolight period is one element that can be manipulated when cockatiels are kept indoors. Cockatiels normally require at least 10 hours of darkness each night and hens may be stimulated to lay eggs when they are exposed to an increase in the amount of daylight hours they receive. In the wild, increased daylight means more time for parent cockatiels to search for food for their hungry chicks, which adds to the clutches' chance for survival. To reverse such a hormonal trigger, a decrease in the amount of daylight hours and a corresponding increase in the hours of darkness, may be enough to stop over-stimulated birds from future laying. Don't overdo the exercise and make certain your bird has enough light to remain healthy, psychologically happy, and able to eat.

    In the wild, cockatiels will search out seeding grasses to feed their chicks. Eliminating or cutting back on the amount of daily soft foods you provide, for example, soaked, sprouted seeds, egg food, or any table foods, in combination with the reduction of other stimulating elements such as the photolight period, might help deter egg-laying. It is crucial that you still provide optimum nutrition at this stressful time and make certain birds are actually eating.

    Some hens will very nearly starve to death rather than leave their eggs to feed. Under normal circumstances, the male will share in the incubation duties, so to aid your hen, place favorite foods within easy reach. Surround the hen with a layer of her normal diet, so she may eat while incubating her clutch. This is not the time to start converting a bird to a pelleted diet. Millet spray placed within easy reach is almost never refused and will add calories to the diet. In the event your hen is very thin from not eating, do not deprive her of any soft foods, table foods, or favorites such as corn, whole-wheat bread, or other easy to eat choices she desires.

    To disrupt the chosen nest site, wait until the hen has abandoned her clutch of eggs, usually after the 18-22 day incubation period -- depending upon when the hen first starts to lay -- then move her to another location. A further disorientation could include returning her to a flight cage, changing her cage, transferring her to another room, or other disruption to her routine home.

    The most difficult condition would be to remove a bonded mate if one is present, which may work. If the hen is attached to a male, the birds may continue to worry and call out to one another. This may be more stressful than helpful. It may be easier to manipulate the other factors mentioned above.

    Finally, in more serious cases, veterinary treatment should be sought from a board certified diplomate in avian medicine. A trained avian veterinarian may recommend hormonal therapy, or in severe cases, surgical removal of the oviduct -- hysterectomy. An exciting event on the horizon is the development of a vaccine pZP, porcine zona pellucida, from swine, that has been found to be a safe, effective immunocontraceptive in several animal studies including horses and elephants. Studies are underway to see if the vaccine, which affects the yolk sac membrane, will prevent ovulation in birds. In essence, the vaccine could be an effective birth control option that prevents birds from laying eggs. Future studies will reveal additional information on the vaccine, its efficacy, and whether repeated vaccinations will have any long-term effects.

    For information on a board certified avian diplomate in your area, contact the Association of Avian Veterinarians, P.O. Box 811720, Boca Raton, FL 33481; (561) 393-8901 or (561) 393-8902.
    

LINDA S. RUBIN is an avicultural writer, editor, speaker, and judge, and an aviculturist for 24 years. She is vice president of the North American Parrot Society Inc. and public relations director of the American Federation of Aviculture Inc. She self-published four books on cockatiel genetics and color mutations and is the author of The Ultimate Parrot Guide and Multiple Bird Households. She can be contacted at: LSRaves@aol.com.