Passive acoustic monitoring provides a fresh perspective on fundamental ecological questions

Passive acoustic monitoring (PAM) has emerged as a transformative tool for applied ecology, conservation and biodiversity monitoring, but its potential contribution to fundamental ecology is less often discussed, and fundamental PAM studies tend to be descriptive, rather than mechanistic. Here, we chart the most promising directions for ecologists wishing to use the suite of currently available acoustic methods to address long-standing fundamental questions in ecology and explore new avenues of research. In both terrestrial and aquatic habitats, PAM provides an opportunity to ask questions across multiple spatial scales and at fine temporal resolution, and to capture phenomena or species that are difficult to observe. In combination with traditional approaches to data collection, PAM could release ecologists from myriad limitations that have, at times, precluded mechanistic understanding. We discuss several case studies to demonstrate the potential contribution of PAM to biodiversity estimation, population trend analysis, assessing climate change impacts on phenology and distribution, and understanding disturbance and recovery dynamics. We also highlight what is on the horizon for PAM, in terms of near-future technological and methodological developments that have the potential to provide advances in coming years. Overall, we illustrate how ecologists can harness the power of PAM to address fundamental ecological questions in an era of ecology no longer characterised by data limitation

Breeding records of the birds of south-east Sulawesi, Indonesia: a collation of observations encompassing nearly 20 years of research in Wallacea

The islands of the Wallacean biodiversity hotspot support diverse and highly endemic bird communities, yet remain ornithologically poorly studied. There is a particular paucity of data regarding breeding biology for the region\u27s birds. Here, we help to address this research gap by collating observations of breeding evidence made during nearly 20 years of field work between 1999 and 2018 in south-east Sulawesi and its offshore islands. Data were collected between April and September, with a special focus on July and August, which is the dry season across the southern half of Sulawesi. In total, we summarise 1,064 observations of potential breeding in 66 species, of which 27 are Wallacean endemics (including the Critically Endangered Maleo Macrocephalon maleo), and 39 species of wider range (including the Endangered Milky Stork Mycteria cinerea). Records include species with little or no previously published information on their breeding biology, such as Pygmy Hanging Parrot Loriculus exilis, Sulawesi Pitta Erythropitta celebensis and an undescribed Zosterops species, provisionally referred to as Wangi-wangi White-eye