Individual study: Successful artificial rearing, captive breeding and reintroduction of two Hawaiian thrushes
Kuehler C., Lieberman A., Oesterle P., Powers A.T., Kuhn M., Snetsinger T.J., Harrity P., Tweed E.J., Fancy S.G., Woodworth B.L. & Telfer T. (2000) Development of restoration techniques for Hawaiian thrushes: Collection of wild eggs, artificial incubation, hand-rearing, captive-breeding, and re-introduction to the wild. Zoo Biology, 19, 263-277
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Release captive-bred individuals into the wild to restore or augment wild populations of songbirds
A replicated study in 1995-6 on Hawaii, USA (Kuehler et al. 2000), found that 80% of 25 captive-bred omao Myadestes obscurus (a thrush) survived for at least 30 days after being released, with at least two chicks being raised. The same study found that 14 (six male, eight female) captive-bred puaiohi Myadestes palmeri (a critically endangered thrush) released at a marshland site on Kaua’i, Hawaii, USA, in 1999 successfully fledged at least seven chicks (from six pairs). Both species were ‘hacked’ by being kept in predator-proof cages at the release site for 6-14 days before release. Food was provided for 17 days after release and predators (feral cats and rats) were poisoned and trapped for 2.5 months before the first puaiohi releases. Details of survival are provided in Tweed et al. 2003. This study is also discussed in ‘Use captive breeding to increase or maintain populations’ and ‘Artificially incubate and hand-rear birds in captivity’.
Use captive breeding to increase or maintain populations of songbirds
A small study at a breeding centre on Kauai, Hawaii, USA (Kuehler et al. 2000), found that four out of five pairs of hand-reared puaiohi, Myadestes palmeri, (a critically endangered thrush) successfully formed pairs and laid a total of 39 eggs in 1998. Birds were taken as eggs from wild nests and artificially incubated (see ‘Artificially incubate and hand-rear birds in captivity’). Releases are discussed in ‘Release captive-bred individuals’.
Artificially incubate and hand-rear songbirds in captivity
Two replicated studies from 1995-9 at breeding centres in Hawaii, USA (Kuehler et al. 2000), found that hatching rates for artificially incubated wild-laid eggs were 93% for 29 omao Myadestes obscurus (a thrush) and 91% for 43 puaiohi M. palmeri (eggs consisted of both captive-laid and wild). Two out of five parent-incubated puaiohi eggs also hatched, whilst an additional 15 eggs were not viable. Both species were hand-reared, with 93% of omao and 92% of puaiohi chicks surviving until 30 days old (producing a total of 38 fledged chicks during 1996-8). The two parent-hatched chicks also survived. Eggs were incubated under a 37.2oC dry bulb and a 26.7-31.1oC wet bulb. Chicks were fed a high protein diet of insects, egg and fruit, initially provided every hour but with decreasing frequency as chicks grew. This study is also discussed in ‘Use captive breeding to increase or maintain populations’ and ‘Release captive-bred individuals’.