Hand-Rearing Techniques Will Before the Colonial Waterbird Group, Dr
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Hand-rearing T he tremendous worldwide technological In 1977 Brookfield Zoo expanding its and social changes of the past one hundred Techniques collection by acquiring a group of six years have placed unbearable pressures on Hadada Ibis, Hagedashia hagedash. In our planet's wildlife. The growing list of for appearance the Hadada is a medium-sized extinct and vanishing species leaves the ibis with grey-brown body plumage. The serious aviculturalist with no choice. Suc IBI~ wing coverts are an iridescent green and it cessful and sustainable captive reproduc bears a white streak on each cheek. The tion seems undeniably necessary for the by Ralph M. Piland Hadada is primarily a bird of open forest long-term survival of many animal forms. Assistant Lead Keeper and savannah. Its range seems to be At Brookfield Zoo we regard hand-rearing and limited particularly to wooded streams as one of many tools to be utilized in the Dennis S. Decourcey and watercourses, although it has been quest for successful captive propagation Superintendent of Birds observed in coastal mangrove swamps. programs. Hand-rearing has been utilized Chicago Zoological Society Geographically its prime occurrence is to achieve two distinct and specific goals. Brookfield, Illinois along the southeastern portion of Africa, First, among species known to be indeter but it crosses the continent equatorially to minate layers, eggs may be removed from mythology with wisdom and fertility, is the west coast. Despite the fact that the the nest inducing the female to produce now extinct within Egypt - a victim of Hadada occurs commonly throughout its greater than normal quantities of eggs. habitat destruction. In a paper presented range, it has seldom been kept or exhibited Successful hand-rearing techniques will before the Colonial Waterbird Group, Dr. in zoological gardens. In 1978 Brookfield thereby increase that species' reproductive George Archibald and Dr. Sharon Lantis Zoo became the first institution to have success. Secondly, given instances of of the International Crane Foundation this species successfully reproduce. abandoned nests or high neo-natal mor report that, "Today the (Japanese) crested It has been our experience that captive tality, successful hand-rearing techniques ibis is perhaps the world's most en ibis reproduction is prone to the same may be used to increase a species' dangered avian species with but eight sur prime nestling mortality factors attributed reproductive success. Increased captive vivors remaining in the wild in Japan, two to wild populations. Skead (1951) and reproduction for the broadest possible in South Korea, and an undetermined Raseroka (1975) report that Hadada Ibis spectrum of avian species must be the final number (if any) in China, North Korea, young apparently often fall to their death goal. In that vein we would to com and the USSR. The Japanese population from rudely constructed nests. Urban municate preliminary results from our has not reproduced since 1973." Clearly (1974) attributes nest falls as a mortality hand-rearings of two related species. there is a need for effective captive pro factor in selected Sacred Ibis populations, The family Threskiornithidae - the pagation and avicultural expertise for this with nest abandonment playing a prime ibises and spoonbills - has long captured avian group. role in populations not nesting in high the interest and imagination of man. Ar Although the world of taxonomy is re trees. Predation was not reported as a tistic renderings depicting the distinctive nowned for its disagreements and revolu significant nestling mortality factor. Ibises bill shapes characteristic of this avian tions, it is generally held that the subfamily are indeterminate layers and therefore we family have been discovered decorating Threskiornithidae, the ibises, is com have attempted to maximize the reproduc the walls of Neolithic caves. The very prised of twenty-six species with nearly tive rate and success of our ibis collection name Sacred Ibis is derivative of the global distribution. The ibis is a moderate by supplementing the natural parent rear veneration once bestowed upon an ibis sized bird with long legs and unwebbed ing process with artificial incubation and species. Hieroglyphics adorning ancient feet suitable for wading. The most charac hand-rearing. In that vein, we have Egyptian monuments and artifacts fre teristic feature of an ibis is its long, slender, developed the procedures recounted quently depict the easily recognizable decurved bill. The Chicago Zoological below. silhouette of an ibis. The Sacred Ibis, often Society currently maintains two species of All ibis eggs removed for artificial incu associated with the Egyptian deity Thoth, ibis at its Brookfield Zoo. The Sacred Ibis bation are placed in forced air incubators was frequently mummified and placed in Threskiornis aethiopicus has long been a and maintained at 97.5 °F. with wet bulb elaborate tombs and pyramids. resident of the Aquatic Bird House, with reading of 80.0°F. The eggs are automat Yet this fascination, which has our current flock containing some in ically rotated 90 degrees every hour. After benefited the artistry and mythology of dividuals approaching thirty years of age. pipping eggs are transferred to a glass man, has held few benefits for its original The adult Sacred Ibis exhibits primarily a fronted hatcher which allows closer obser stimulus. The affection of man has been white plumage, although soiling may com vation. Contrary to figures in current selective and fickle. A small number of ibis promise the purity of the whiteness. The literature (Urban, 1974, reports 28-29 species have appeared in avicultural or head and neck area are bare skin, a dull days; Skead, 1951, reports approximately zoological collections. And an even black in color. The tips of the primary and 26 days; Raseroka, 1975, reports 25-28 smaller number have responded to at secondary feathers are also black. Addi days) all our eggs have hatched following a tempts at captive propagation. But tax tionally, blue-black decorative scapular 22 day incubation period. All eggs have onomists recognize over twenty species of plumes are evident on birds in breeding hatched unassisted, with most chicks com ibis representing many varied geograph condition. The Sacred Ibis occupies pleting the hatch within 24 hours of pip ical and ecological adaptations. Despite tropical and sub-tropical habitats, occur ping. Hatching weights have generally the thousands of years of selective atten ring most frequently by inland lakes and ranged between 40 and 50 grams. Immedi tion from man little is known of many of rivers and in cultivated areas. Geographi ately after hatching the abdominal areas of these animals. Like so much of the world's cally the extent of its distribution is the chicks are swabbed with an iodine flora and fauna, ibises must be viewed as somewhat disputed. It is primarily asso solution to prevent the possibility of infec endangered and vanishing animals. It is ciated with African fauna, but also occurs tion originating in the umbilical area. Ibis perhaps a prime irony that the so-called in western Asia and southwestern Pacific chicks are best described as semi-altricial. "Sacred" ibis, associated in Egyptian islands. That is, although ptilopaedic, they are 41 nidicolous with the eyes remaining effec dramatic extension of the tibiotarsal and tively closed for about five days. The tarsometatarsal bones. Particular care chicks are provided with a substrate of must be given to calcium supplementation small twigs arranged to simulate a nest cup to meet these extraordinary growth within a stainless steel bowl. Although the demands. The mixture is not chemically use of the twigs poses minor hindrance to predigested. the maintenance of optimum hygenic con Initially the diet was prepared every 48 ditions it is felt that the provision of a hours and maintained in a refrigerated natural substrate is a critical factor to state. Dr. Frank Wright, formerly of the proper development. Ibis chicks have, in Brookfield Zoo veterinary staff, subse the past, displayed considerable difficulty quently suggested that a more optimum in keeping their legs positioned beneath level of diet sanitation could be main themselves on smooth surfaces. Upon tained by quick freezing the diet prepara hatching the chicks are not capable of tion immediately after production. Our standing, but are capable of grasping light current procedure is to immediately ly with the feet. The body weight of the transfer the blended paste to pre-sterilized chicks rests on the intratarsal or heel joint, (ethylene oxide process) and sealable SHIPPED ANYWHERE IN which develops a characteristic protective plastic bags. The material is then quickly 0 THE UNITED STATES pad. The chicks are almost immediately frozen and maintained in that state until CALL OR WRITE FOR PRICES I capable of limited locomotion, which is needed. This procedure, in addition to AND AVAILABILITY ~ achieved by shuffling along the heel joints. providing a high level of hygiene, is much The young ibis quickly express this limited more flexible and easily adaptable to mobility by moving toward a food source feeding various numbers of chicks. Im THE A VICULTURAL and by backing to the edge of the nest to mediately prior to a scheduled feeding a SOCIETY defecate. It is the latter inclination which bag containing an appropriate amount of (founded 1894) apparently contributes to the high nestling prepared diet is thawed in heated water. mortality rate. The warmed paste is then mixed with suffi has an international membership, Ibis feed their young by regurgitation. cient hot water to produce a semi-liquid who receive and contribute to We attempted to replicate the physical consistency of about body temperature. It The A vicultural Magazine', the consistency of regurgitated material in our is believe that the temperature of the food oldest and most revered journal hand-rearing diet. The diet is based upon material is a critical factor.