Conserving the Last Native Frugivore of Kauaʻi: Evaluating Management for the Puaiohi (Myadestes palmeri)

Abstract

Biodiversity is in crisis worldwide as invasive predators accelerate extinction rates, especially on islands. In Hawaiʻi, the critically endangered puaiohi (Myadestes palmeri), the last frugivore on Kauaʻi, faces severe predation by invasive rats (Rattus spp.). Goodnature A24 self-resetting traps are widely used to reduce predator pressure, yet their effectiveness and potential risks remain uncertain. I addressed these questions through two complementary studies. First, I used Cormack–Jolly–Seber models to analyze capture–recapture data from 209 puaiohi monitored from 2020 to 2023 in areas with and without A24 trapping. Survival improved in trapped areas, with a strong increase for adult females and a marginal increase for juveniles, while adult males maintained high survival across treatments. Second, I deployed trail cameras to test whether puaiohi were attracted to traps; encounter rates did not differ among treatments. These results show that A24s improve survival, supporting their use in adaptive conservation strategies.