Adapting conservation breeding techniques using a data‐driven approach to restore the ‘Alalā (Hawaiian crow, Corvus hawaiiensis)

Abstract

For some critically endangered species, conservation breeding is a vital steppingstone toward re‐establishing wild populations. The ‘Alalā (Hawaiian crow, Corvus hawaiiensis), currently extinct in the wild, exists today only in a conservation breeding program, which, for many years, utilized successful hands‐on husbandry approaches such as separating and resocializing pairs, providing partially manmade nests, artificially incubating eggs, and puppet rearing nestlings. Yet, a top priority of any conservation breeding program is to retain natural behaviors essential to postrelease survival and reproduction, to achieve successful reintroduction and restoration to the wild. We describe how we are adapting ‘Alalā husbandry techniques to strengthen pair bonds through full‐time socialization, enable pairs to build robust nests, encourage females to incubate eggs to hatch, and provide pairs and their offspring with vital parental rearing experiences. We discuss the use of standardized, data‐driven methods to objectively track our progress towards successful parental breeding and to select release candidates based on their likelihood to survive and breed in the wild. The information shared in this report can be applied to other conservation breeding programs, particularly those implementing or transitioning to husbandry techniques geared towards preparing species to thrive in the wild.

The influence of pair duration on reproductive success in the monogamous ‘Alalā (Hawaiian crow, Corvus hawaiiensis)

“…Throughout our study, caretakers recorded nest progress data to capture whether each pair had placed no sticks, a few sticks, many sticks, or constructed a nest with a visible nesting cup, on one or more nest platforms in their aviary, at least three times per week, beginning March 1 st , until females laid their first clutch. Nests with eggs were assigned a discrete, ordinal nest quality score, ranging from 1 (worst nest; essentially no attempt at nest building) to 5 (best nest) at the time of lay (Flanagan et al, 2023). In addition to collecting data on nest progress and nest quality, caretakers monitored and recorded data on egg laying, hatching, and nestling survival.…”

“…After a sufficiently large assurance population was established, from ~2018 onward, (with ~140 living individuals), the breeding program moved away from intensive, traditional avicultural methods (involving artificial incubation and puppetrearing offspring) to parental breeding with pairs being predominantly full-time socialized to allow for coordinated breeding behaviors to occur. The transition to parental breeding was an important shift in management intended to encourage the birds to successfully build nests, incubate eggs, and parent-rear nestlings, with important implications for animal welfare and, eventually, reintroduction to the wild (Flanagan et al, 2023).…”