Action: Artificially incubate and hand-rear storks and ibises in captivity
A small study in the USA describes the successful artificial incubation and hand-rearing of two Abdim’s stork Ciconia abdimii chicks, whilst a review of northern bald ibis Geronticus eremita conservation found that only very intensive rearing of a small number of chicks appeared to allow strong bonds to form between chicks – thought to be important for the successful release of birds into the wild.
Artificial incubation involves removing eggs from incubating parents and using an incubator to hatch them. Techniques can be extremely complex, with precision humidity and temperature control and turning of the eggs to ensure correct development Hand-rearing can be used with chicks from artificially-incubated eggs or with chicks removed from parents after hatching and involves manually feeding chicks until independence. Both techniques can be used to encourage parents to produce more offspring, or when naturally-raised chicks and eggs have low survival.
Supporting evidence from individual studies
A small study the Audubon Park Zoo, New Orleans, USA, in 1983 (Farnell & Shannon 1987) found that a pair of Abdim’s storks Ciconia abdimii successfully bred in captivity (see ‘Use captive breeding to increase or maintain populations’), producing two eggs which were artificially incubated and hand-reared. The two chicks successfully integrated with the captive population and displayed normal behaviours. The eggs were incubated in a forced-air incubator at 36.9°C, moved to a 34°C brooder after hatching, with the temperature gradually reduced to 26°C by the time chicks were four weeks old. Hand-rearing consisted of seven feeds a day until four weeks old, when they were fed three times a day and then once a day from seven weeks old. Food consisted of commercial bird-of-prey food, fish, insects and yoghurt.
A 2007 review of northern bald ibis (waldrapp) Geronticus eremita conservation (Bowden et al. 2007) found that intensive hand-rearing of ibis chicks by a small number of human foster-parents appeared to lead to the formation of strong bonds between chicks which appear important in successful releases of the species. This study is also discussed in ‘Use captive breeding to increase or maintain populations’, ‘Release captive-bred individuals into the wild to restore or augment wild populations’, ‘Use holding pens at release sites’, ‘Release birds as adults or sub-adults, not juveniles’, ‘Clip birds’ wings on release’, ‘Use microlites to help birds migrate’ and ‘Foster birds with non-conspecifics’.
- Farnell G. & Shannon P.W. (1987) The breeding of Abdim's storks at the Audubon Park Zoo. Colonial Waterbirds, 10, 251-254
- Bowden C.G.R., Boehm C., Jordan M.J.R. & Smith K.W. (2007) Why is reintroduction of northern bald ibis Geronticus eremita so complicated? An overview of recent progress and potential. Pages 27-35 in: Toronto, Onatario, Canada.