Using captive-bred helmeted honeyeaters to establish a new population and supplement an existing population, Victoria, Australia

Summary

The helmeted honeyeater (Lichenostomus melanops cassidix), Critically Endangered and reduced to about 15 breeding pairs in a single remnant population at Yellingbo, Victoria, has been the focus of a 20-year recovery program using captive-bred birds both to found a second wild population in Bunyip State Park and to supplement the declining Yellingbo population. Captive management began in 1989 with heterozygosity preserved through zoo studbook protocols and cross-population egg and chick transfers; a series of release-method trials tested wild-bird translocation (mostly unsuccessful, birds returning home or disappearing), decoy males to attract dispersing females (no success), and family-group releases from on-site aviaries, eventually finding that hard-releasing groups of independent, first-year young after up to seven nights in an on-site aviary worked best. Reintroduction to Bunyip State Park began in 2001 with 11 birds and continued annually to a total of 108 birds over nine years across three release sites established in 2001, 2005 and 2008; breeding began in the program's second year and nest attempts have increased steadily since. Of 95 captive-bred birds released at Bunyip through 2008, 31 (33%) survived at least a year and 21 (22%) bred successfully in the wild; at Yellingbo, of 59 supplemental releases, 39% survived a year and 24% bred. Major difficulties included a high proportion of infertile eggs and below-expected hatching and fledging success in the captive colony, and premature detachment of tracking transmitters limiting monitoring. The project rates itself Successful, citing established breeding at multiple release sites as evidence captive-bred birds can found and sustain new wild populations.