We reintroduced 25 captive-reared ‘Oma‘o (Myadestes obscurus) and translocated 16 wild-caught ‘Oma‘o to former range in the Pu‘u Wa‘awa‘a Wildlife Sanctuary on the island of Hawai‘i to develop and refine methods that might be used in the recovery of the closely related and critically endangered Puaiohi (Myadestes palmeri) on Kaua‘i. Captive-reared ‘Oma‘o were soft-released from two hacking towers at 66-57 days of age, whereas wild birds (all adults) were hard-released on the same day as capture or after a l-9 day holding period. The fate of all birds was monitored daily for two months using radiotelemetry. Only 16 of 76 (21%) wild-caught ‘Oma‘o were translocated because of problems with active avian poxlike lesions, an imbalanced sex ratio, or because birds would not eat during holding. Survival to 30 days post-release was similar for birds released by the two methods: three captive-reared ‘Oma‘o were killed by predators, and four wild ‘Oma‘o died of handling/transport stress. ‘Oma‘o populations are highly male biased, and a sex ratio of captive-hatched eggs of 18 males to 6 females suggests that the sex ratio may not be 1:1 at hatching. Translocation of hatching-year ‘Oma‘o would not be practical because of very low capture success for juvenile ‘Oma‘o and the skewed sex ratio. Fidelity to the release site was higher for captive-reared birds, and this approach is less expensive for ‘Oma‘o and more likely to result in successful establishment of a new population in continuous habitat.
