Early Chick Mortality

by Patricia Tucker


The most heartbreaking complication to occur in our aviaries is Early Chick Mortality. (ECM), and inevitably, we will all encounter this phenomenon in some form during the course of our avicultural experience. The definition of Early Chick Mortality, for the purpose of this writing, is the loss of chicks in the nest between the ages of 0 and 4 days.

The causes for this phenomenon are numerous, but seem to encompass three basic categories:

Behavioral

Accidental

Physiological

The most common cause of Early Chick Mortality in cockatiels, based on my experience to date, is behavioral and usually occurs with young, inexperienced birds when they are faced with a large brood or too many chicks hatch simultaneously. In these cases, the parents voluntarily reduce the clutch size by rejecting the youngest chick. This behavior is principally due to the overburden of an unusually large clutch, thus ensuring the survival of the brood. Another behavioral cause of ECM includes the rejection of young because of visual differences such as the presence of a red-eyed chick amongst black-eyed clutchmates or a whiteface chick (covered with white down) in a nest of yellow-downed siblings. In the above situations, with careful nest monitoring, it is possible to successfully save the life of a rejected chick, but the beginner should be aware that it is risky to interfere with ANY nest during this high-risk period. Parent birds are extremely protective of their brood during their first week of life and unless the birds exit the nest or are extremely tame, there is a danger of the remaining chicks becoming injured during the removal of the rejected chick. Assuming parents allow nest inspection and a problem is identified, the chick should be removed periodically and given a supplementary feeding. This will ensure that the chick remains strong enough to beg in the nest and once the chick is 4 or 5 days old, the parents usually take over the feedings completely.

Another behaviorally-caused rejection I have witnessed occurs when chicks are FOSTERED from their natural parents due to inadequate feeding or abusiveness, such as feather picking. This behavior usually manifests itself when the relative age of the fostered chick is substantially younger or older than that of the foster parent's natural chicks. In these situations, the foster parents may not be willing or able to feed the chick and may either reject it totally or feed it with disastrous results. Ideally, the median age of fostered chicks should equal that of the natural chicks in the nest, with a variance of 2 or 3 days at the outside. If the appropriate circumstances are not present, a safer alternative may be to pull the chick for handfeeding. However, this is a substantial undertaking at such a tender age. It will be necessary to feed the chick at two-hour intervals from 6:00 AM to Midnight with one feeding at 3:00 AM for the first few days to ensure survival.

Another potential cause of Early Chick Mortality, which is difficult to diagnose with any measure of accuracy, is accidental injury in the nest. Accidental ECM, although highly speculative, appears to be either parent or sibling-caused. In these situations, unlike cases of rejection, the chick is usually found dead in the nest with a full crop. Although illness can't be ruled out without the benefit of a necropsy (postmortem exam) which is likely to be inconclusive at such a young age, it is reasonable to assume that the cause of death was accidental if the clutchmates are developing normally. Speculative causes for parental or sibling-caused injury in the nest would include occurrences as trampling, smothering or aspiration. Unfortunately, there are usually no warning signs to allow the aviculturist the opportunity to prevent ECM as a result of accidents of this nature. The most common explanation for injuries in the nest involving trampling or smothering is interference from an outside force which initiates enough fear in the parents to cause a accidental injury. For example, a "night fright" while parents occupy the nest can be lethal to newly hatched chicks. Experience has taught me that unnecessary handling of chicks under the age of 7 days is a dangerous practice. Aviculturists who are allowing their chicks to be parent- raised gain no ground by beginning to handle them earlier than 2 weeks of age, and nest cleaning should not be necessary until the chicks have reached 5 or 6 days. I do, however, recommend careful nest monitoring so that reversible ECM symptoms can be identified and corrective action taken.

The third and most mysterious cause of Early Chick Mortality is physiological. This category encompasses all aspects of physical problems running the gamut from deformities to infections to dietary problems. The physiological symptoms that I have been able to identify are:

Excessive Weakness
Deformity
Nutritional Deficiency
Infection

Excessive Weakness, although somewhat vague in description, usually has physiological implications. A chick displaying excessive weakness, due to dietary influences, poor incubation, or poor breeding practices such as inbreeding, may succumb to ECM by way of a basic law of nature, "Survival of the Fittest." In a large brood, a weak chick may not have sufficient strength to complete successfully with its clutchmates for food, and without adequate food will not survive. Early identification of this problem and supplementary feedings in the nest can be extremely successful in revitalizing a chick who is showing excessive weakness, providing there is no infection present. A second manifestation of Excessive Weakness is seen in full-term dead-in-shell chicks. In cases of this nature, when the shell is opened and the positioning of the chick is found to be correct, Excessive Weakness due to infection or genetic makeup should be considered.

Another possible cause of Early Chick Mortality is deformity; a result of improper development of the chick, possibly due to infection, genetic weakness, or dietary deficiency. I experienced an early death due to deformity in 1986 with a chick who's beak was not properly formed upon hatching. As a result, the parents refused to feed the chick, either because they were physically unable to or because they knew the chick would ultimately not survive. Because of the severity of this deformity, I chose not to administer supplementary feedings since I strongly suspected that this chick, had it survived, would never have been self-sustaining.

A particularly disturbing cause of ECM, which I was made aware of recently during a consultation with a fellow aviculturist, comprises two categories: physiological and behavioral. In this situation, a parent (in this case, the Sire) chewed the toes off his chicks, starting with the youngest. Since this was a first-breeding, the plan was to remove each parent separately for a period of time to determine which parent was responsible for the mutilation. When the male was removed, the chewing ceased and the mystery was solved. However, the interesting aspect here was that the chicks were showing abnormalities of the feet (believed to be caused by a calcium deficiency in the hen), and this could have provoked the male to initiate this action. The upside of this story is that one of the chicks did survive due to the initiation of a dietary correction. Extra calcium, in the form of MSA, manufactured by Nekton Products, and a powdered vitamin supplements were added to cooked rice which the hen eagerly devoured in her diligent attempt to raise this surviving chick on her own. Fortunately, the surviving chick (who has since feathered out as a Pearl) was the first hatched and had only minor injuries. She improved dramatically, due to the dietary supplementation, and at this writing is beginning to eat on her own.

The final and most disturbing physiological cause of ECM is illness resulting from infection. In these cases, parent birds have been known to exhibit behavior ranging from rejection to outright murder. The reality here is that this is nature's way of eliminating imperfect life-forms; however, early detection and appropriate treatment by an Avian Specialist have proven successful in these cases. In my opinion, illness in a newly-hatched chick is indicative of illness in one or both of the parents. If an entire clutch of new hatchlings are rejected or killed, the parents should be examined and treated by an Avian Specialist to determine the physiological problem. I am told that this occurrence can be strictly behavioral in cockatiels; however, since I have never experienced this situation, I assume it is rare.

Surprisingly, adult birds can harbor an infection which may not cause them visual distress, but excessive Early Chick Mortality, due to the transmission of infection is a warning sign which should not be ignored. It is wiser to keep fewer birds for which you can afford an occasional consultation with an Avian Specialist and appropriate diagnostic testing, than to allow a physiological disorder a chance to establish itself in your flock.

Experiencing Early Chick Mortality in some form is inevitable for the aviculturist, whether in the form of a full-term dead-in-shell chick or a 2-3 day old baby found dead in the nest for reasons apparently unknown. This is one aspect of aviculture I find difficult to take lightly and will never stop trying to understand it. The more we learn about this phenomenon, the fewer ECM victims there will be in our aviaries.