Hand-rearing is a time consuming task, especially when the chicks are small. On hatching all species require feedings every two hours from 0600-2300 hours. Most species can forego a night feeding at around 0300 hours if they hatch with a weight of more than 4 grams. As the chicks grow and the crop becomes more capacious, the span between feedings can become longer. In other words, feedings will be required every 3-4 hours from 0600-2300 hrs.
In my experience a chick’s crop should never empty during the day. Many hobbyists will argue that if the chick is fed with food still in the crop it will suffer from crop stasis. This suggests a management flaw as it makes no biological sense that the crop must empty. Clearly in the wild the parents do not allow the crop to empty before feeding the chicks again.
In more than 40 years’ of hand-rearing, I have always fed young when they still have food in the crop. This is important because hungry chicks will grasp each other’s bill and pump, often damaging the delicate beak; they will cry incessantly; and they will eat the nesting substrate. In some cases even their growth can become affected. In the wild chicks never cry incessantly (or they would alert prey of their presence), they never have an empty crop during the day, and they never eat the nest substrate. In aviculture I believe we need to strive for this and this can only be achieved by keeping the chicks satiated.
Another important point in keeping young content is meeting the higher fat requirements of most species; wild parrots clearly select foods for feeding their young that are rich in fats. When the chick is well fed and the fat content is adequate, they sleep for much of the day, waking up periodically to preen and flap their wings. They never need to eat the nesting substrate because physically and mentally they feel satiated.
Hand-rearing is time consuming. Not only must the chick be fed throughout the day, but it must also be cleaned. Formula will need preparation and the feeding instruments will need to be cleaned and disinfected after each feeding. The more chicks being hand-reared, the more time that will be consumed by the process. This means that for a working hobbyist the process may not be practical, except if they have a family member or friend that can assist or there is a commercial hand-rearer whose job is to rear the young to an agreed stage of development.
When hand-rearing is not possible, the breeder can ether allow the parents to rear their young or the eggs or chicks can be fostered under another pair. Which of these directions the breeder opts for depends on many factors.
Most parrots species nest once a year if they are allowed to rear their young, but if the eggs or chicks are taken before they are a few weeks old, most pairs will produce a replacement clutch. This intensive management is important when dealing with a rare species, or a species whose genetics are poorly represented in aviculture. Years ago I incubated every egg laid by a pair of Hispaniolan Conures Psittacara chloropterus and then hand-reared the young. This was done because they were the only pair at the time in the USA. In a span of three years, I produced nearly 40 young, including several sent to Loro Parque who in turn contributed to the European genepool. Had the parents been allowed to incubate and rear their chicks, I would have produced perhaps 12 young during the same span of time.
Using foster parents requires some understanding of the species being used. Some parrot nestlings feed their chicks initially on their backs; others feed them standing up. Some chicks are naked on hatching; others are thickly downed. Some display a strong feeding response. In others the response is poor. Because of these species specific idiosyncrasies, finding foster parents whose own chicks will resemble those being placed under their care is important. I find that conures can rear macaws and amazons very successfully, that Ring-necked Parakeets Psittacula krameri will rear cockatoos and that Red-rumped Parrots Psephotus haematonotus will feed the chicks of a broad array of Australian parrots and parakeets. Knowing the history of the pair, their tolerance for intrusion and their brooding habits is important. I add here brooding habits because some species stop brooding their young very early, but the chicks of some species require warmth much longer. I once tried to incubate the eggs of Bonaire Conures Aratinga pertinax xanthogenia under Red-fronted Kakarikis Cyanoramphus novaezelandiae. The chicks perished because the kakarikis ceased to brood them far too early.
How chicks are added to the nest is important. If the foster chicks are being added to a nest containing young, these should be placed within the group. They should be of approximately the same size. Adding too small or too large a chick increases the risk of it being rejected or killed. I like to add chicks very early in the morning after having removed the food from the pair the night before. On being offered food, both members of the pair will descend to feed. This gives me unfettered access to the nest. They will then rush back to feed their young and pay less attention to each individual chick.
When eggs are fostered into a nest, they should be approximately the same size. This is important because a small bird will be unable to incubate a large egg, and a large bird may crush a small egg. Also, the clutch should not be so large that the incubating bird will be unable to adequately brood the eggs. If the nest already contains partly developed egg, the new eggs should also be partly developed. This prevents the eggs from being covered in feces from hatched chicks or the chicks being crowded out at feeding time by much larger nest mates. The best foster pairs are those that have a clear clutch of eggs. Add the eggs as early as possible to prevent the eggs being abandoned as a result of the internal clock in the incubating bird telling it to smash the eggs and produce another clutch.
Fostering is an excellent tool for the busy person, but it requires an understanding of the biology of both the natural and the foster parents, sufficient pairs with a known history to have a predictable outcome, and pairs whose eggs or chick are about the same age as those in the foster nest.
author: Tony Silva
Title photo: (c) Tony Silva