Chronic egg laying is a maladaptive, behavioural disorder commonly seen in pet birds which repeatedly lay clutches of infertile eggs in the absence of a mate. It is particularly common in

cockatiel The cockatiel (; ''Nymphicus hollandicus''), also known as weiro (also spelt weero), or quarrion, is a medium-sized parrot that is a member of its own branch of the cockatoo family endemic to Australia. They are prized as household pets and comp ...

budgerigar The budgerigar ( ; ''Melopsittacus undulatus''), also known as the common parakeet or shell parakeet, is a small, long-tailed, seed-eating parrot usually nicknamed the budgie ( ), or in American English, the parakeet. Budgies are the only spe ...

lovebird Lovebird is the common name for the genus ''Agapornis'', a small group of parrots in the Old World parrot family Psittaculidae. Of the nine species in the genus, all are native to the African continent, with the grey-headed lovebird being native ...

macaw Macaws are a group of New World parrots that are long-tailed and often colorful. They are popular in aviculture or as companion parrots, although there are conservation concerns about several species in the wild. Biology Of the many differe ...

s and

amazon parrot Amazon parrots are parrots in the genus ''Amazona''. They are medium-sized, short-tailed parrots native to the Americas, with their range extending from South America to Mexico and the Caribbean. ''Amazona'' is one of the 92 genera of parrots t ...

s. Birds exhibiting chronic egg laying behavior will frequently lay eggs one after the other without stopping to brood them once the typical clutch size for their particular species has been reached. Excessive egg laying places a strain on the hen's body, depleting resources such as calcium, protein and vitamins from her body and may lead to conditions such as

egg binding Egg binding occurs in animals, such as reptiles or birds, when an egg takes longer than usual to pass out of the reproductive tract. In birds In birds, egg binding may be caused by obesity, nutritional imbalances such as calcium deficiency, envi ...

osteoporosis Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility, and consequent increase in fracture risk. It is the most common reason for a broken bone ...

seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

s, prolapse of the

oviduct The oviduct in mammals, is the passageway from an ovary. In human females this is more usually known as the Fallopian tube or uterine tube. The eggs travel along the oviduct. These eggs will either be fertilized by spermatozoa to become a zygote, o ...

peritonitis Peritonitis is inflammation of the localized or generalized peritoneum, the lining of the inner wall of the abdomen and cover of the abdominal organs. Symptoms may include severe pain, swelling of the abdomen, fever, or weight loss. One part or ...

- which may lead to her death.

Causes

While a single specific cause is unknown, chronic egg laying is believed to be triggered by hormonal imbalances influenced by a series of external factors. As in the

domestic chicken The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult m ...

, female parrots are capable of producing eggs without the involvement of a male - it is a biological process that may be triggered by environmental cues such as day length (days becoming longer, indicating the arrival of spring) and food availability, or the presence of a dark, enclosed space (such as a cupboard or space beneath furniture) in which the bird in question can hide and is not a conscious decision. An overabundance of easily available, nutritious food may trigger the bird's reproductive cycle, as can the presence of a male bird in the vicinity of her cage, or even a circumstance where the hen becomes mistakenly attracted to a mirror or other cage toy. Removing the eggs from a bird demonstrating this behavior may make the problem worse by inducing her to lay even more eggs.

Treatment

Unlike cats, dogs and other pet mammals, parrots are not routinely

neutered Neutering, from the Latin ''neuter'' ('of neither sex'), is the removal of an animal's reproductive organ, either all of it or a considerably large part. The male-specific term is castration, while spaying is usually reserved for female animals. C ...

. While it is possible to spay a female parrot, it is a difficult and dangerous procedure that is seldom performed except in extreme circumstances. Instead, treatment and prevention of chronic egg laying behavior involves behavioral modification and environmental changes. Such changes may include: *Shortening the parrot's perceived day length by putting her to bed early *Denying her access to dark, enclosed spaces *Separating her from any birds to which she appears to be bonded in a sexual manner *Discouraging sexual behaviors from the bird towards humans or favored objects *Regularly changing around the layout of her cage *Permitting the bird to continue sitting on her eggs until she loses interest if she has already laid a clutch and then stopped Hormonal treatment, such as injection of leuprolide acetate (Lupron) or a

deslorelin Deslorelin, sold under the brand names Ovuplant, SucroMate, and Suprelorin among others, is an injectable gonadotropin releasing hormone superagonist (GnRH agonist) which is used in veterinary medicine for various indications. Uses Veterinary ...

implant placed beneath the skin may cause the egg-laying to cease, but does not resolve the underlying cause of the behavior.

References

{{Reflist Abnormal behaviour in animals Animal reproductive system Bird behavior Bird health Oology