Soundscapes are increasingly being used to monitor the status of bird populations. Here, we investigated whether island soundscapes could detect recovery of nesting seabirds following the removal of invasive predators. We recorded soundscapes on 12 islands that were either free from introduced mammalian predators (henceforth predator-free islands), had predators eradicated before the start of our study (restored islands), or still supported introduced mammalian predators (predator islands). Soundscapes from restored islands were more similar to predator-free islands than predator islands, suggesting that soundscapes can document the progress of seabird recovery following the removal of invasive predators. Differences in soundscapes between island types were primarily driven by changes in the acoustic dominance and the temporal and spectral properties of seabird calls, particularly from burrow-nesting seabirds such as storm petrels, prions, and shearwaters. Given the rapid and cost-effective nature of acoustic monitoring, the results suggest that soundscapes have the potential to become part of a standard suite of tools for assessing the progress of seabird recovery after predator eradications.

Keywords: bioacoustics, burrow-nesting seabirds, invasive species, restoration, soundscape ecology.