Rescue, Return and Re-Establishment: Movement Ecology of Repatriated Platypuses Following a Drought-Driven Emergency Rescue

Context Climate-driven droughts increasingly threaten freshwater species, and emergency rescue and repatriation is a critical conservation intervention. The platypus (Ornithorhynchus anatinus), a semi-aquatic monotreme endemic to eastern Australia, is increasingly exposed as droughts intensify. Aims We quantified the post-release movement ecology of repatriated platypuses to evaluate the emergency rescue-and-return intervention. Methods After the severe 2017–19 drought, seven platypuses were rescued from Tidbinbilla Nature Reserve and held at Taronga Zoo; five were returned to their capture sites after ~5 months. Acoustic telemetry across 11 sites over 18 months recorded movements, and Hidden Markov Models identified behavioural states and site-to-site transitions. Key results All five gained body condition in captivity (mean weight gain 36.9%, range 20.6–54.4%). Four were detected for 290–553 days post-release; one female was lost to follow-up after 39 days (minimum first-year survival 0.80). The four females established consistent site preferences; the single male used all 11 sites with more frequent transitions. Activity was positively associated with Hemiptera, Diptera and Gastropoda and negatively with Plecoptera. Conclusions Repatriated platypuses re-established typical movement and foraging patterns within days of release. Implications Emergency rescue and repatriation offers a viable conservation tool for freshwater wildlife under intensifying climate-driven droughts.