Abstract
Hand-rearing birds has generally been avoided at the Franklin Park Zoo Aviary for a variety of reasons. First and foremost is that an animal's natural parents are, by nature's skillful design, much more adept at caring for their young than any well-intentioned keeper. Nature's subtle needs prove difficult to satisfy when attempting to hand-rear a bird. In addition, a keeper's limited and often diverted attention cannot compare with the almost compulsive devotion shown a young bird by its parents.
Almost all birds go through a phenomenon called imprinting, which is a process by which young birds learn to identify with those of their own kind. Hand-reared birds, because of their close association with humans, often become imprinted on their keepers rather than their own species. Upon reaching adulthood, humanimprinted birds sometimes have difficulty relating to other birds which lessens the chance that the bird will accept an appropriate mate and reproduce. Furthermore, these birds are often too friendly and, therefore, vulnerable to the occasional illintentioned zoo visitor.
Lastly, hand-rearing is both time consuming and demanding for the people involved. Much time is spent preparing food, feeding, caring for and just plain worrying about the small charges.
Despite all these drawbacks, handrearing does have its place in captive zoo management. Often birds, through their lack of experience, or because of the unnatural environment imposed on them by captivity, do not complete the normal sequence of incubating and rearing their young. In such situations the young can be justifiably removed from the nest and hand-reared.
Such a situation did arise last spring when Rose and Rags, a recently established pair of grand eclectus parrots, failed for the second time to properly care for their young. This rare and beautiful species has a large number of zoos and aviculturists attempting to raise them. The number raised, though fairly extensive, is very small in comparison to the attempts being made.
The grand eclectus parrot (Eclectus roratus) is indigenous to Australia, New Guinea and most of the South Pacific Islands. They inhabit the dense rainforest treetops, feeding on fruits, nuts, seeds and leafbuds. The male eclectus is a brilliant soft green with red beneath his wings. The shoulders, wings and tail are tipped with blue. The female's coloration is just as outstanding. She has a bright red head fading into a deep blue neck and abdomen. The back and wings are dark maroon with a red tail outlined with orange-yellow.
In the wild, during the breeding season, they go off in pairs to find a deep nest high in a hollow tree. The female lays one to three eggs, which hatch about thirty days later. While the female does all the incubating, the male feeds her and assists in rearing the youngsters once hatched.
Success in breeding eclectus at the Metropolitan Boston Zoos has been noteworthy. Since November of 1973, 40 young have been produced. One breeding pair in particular, called Minnie and Moocher, have raised most of these young themselves and possibly are the most successful breeding pair in captivity. What is even more important is that at least 12 of their offspring throughout the country are producing young of their own.
Although eclectus parrots have been hand raised by the hospital staff at the Metropolitan Zoos, none of the present direct care staff in the aviary had any experience in hand-rearing parrots. Previous bird house staff had had success in rearing parrot-type birds, and thanks to former staff member Gretchen Wilson, much of the experience and observations were recorded and available for reference.
The efforts of the 1983 staff centered around the rejected offspring of the aforementioned Rose and Rags. The initial hand-rearing attempt, under the guidance of Curator of Birds, Bob Wilson, began April 26, when it was decided to pull a two day old chick from the mating pair. The chick had been fed in the nest supplementally over the previous 48 hours with a formula consisting of finely ground monkey chow, peanuts, mynah pellets, sunflower seeds and vitamin supplements, all mixed into water. However, the chick did not seem to be receiving any food from the parents and was growing weaker. It also appeared that it was not being brooded by the female, as it was cold each time it was checked.
The chick was moved to a baby isolette or incubator where the temperature was kept between 90-95 degrees, and a two hour feeding schedule commenced. Food was offered to the youngster in a plastic teaspoon melted and reformed into a funnel-like shape. A spoon was used as opposed to an eyedropper because there is less chance that food will accidentally enter into the chick's windpipe causing it to choke, and because it more closely resembles the natural feeding action between adult and chick. The amount of food and the frequency the chick was fed was determined by the quantity of food remaining in the crop (a small pocket-like projection used for storage at the beginning of a bird's alimentary canal).
Despite our precautions, 24 hours later the chick was dead. It had likely aspirated a too-moist or too-generous portion of formula. Thus began a long standing dread and debate over formula consistency and the amounts fed, but the immediate problem was the second nest-bound chick of the same parents, which had hatched in the interim. It too was failing, so the bird was pulled and hand-rearing commenced once again.