Button-quail (Turnicidae) are a greatly understudied family of birds; their cryptic habits make studying them in the wild challenging. They are known to be quite vocal which could assist with detectability, and so it follows that survey results will be more reliable as knowledge about button-quail vocal repertoire increases. Until recently, there were no published vocal recordings of the Chestnut-backed Button-quail Turnix castanotus, and descriptions and accounts of this species’ vocalisations were limited. We recorded vocalisations of Chestnut-backed Button-quail at six locations across the Northern Territory and Western Australia. Three broad vocalisation types were identified: advertising ooms, drumming, and contact calls. We present descriptions and visual representations of these vocalisations, and draw comparisons with previously published accounts of this species, and other Australian button-quail.
Research into the suitability of autonomous recording units (ARUs) when surveying for vocal species is increasing. Simultaneously, there has been extensive research into methods for efficiently extracting signals of interest from the acoustic data sets that accrue from the deployment of ARUs. For some species, bioacoustic monitoring supported by computerised signal detection offers the only effective and efficient method for widespread survey. In these circumstances, the detection space of both the ARU and the performance of the signal detection process must be considered concurrently, but typically, these two elements have been considered separately. Here, using the Night Parrot (Pezoporus occidentalis) as a case study, we consider both ARU detection space and the signal detection process to develop a robust and repeatable survey protocol for the species. After developing a call recogniser for the Night Parrot, we test its performance on a data set of Night Parrot calls given at a known distance from an array of ARUs. Having established a relationship between ARU type, recogniser performance and distance, we determine the sampling radius of an ARU for a given recogniser score cut-off, and the associated probability of detecting a Night Parrot that calls within that sampling radius. Using these data, we outline how to develop a robust and repeatable survey protocol for the Night Parrot, with a defined probability of detection. This protocol could be adapted for other scenarios where deployment of ARUs is necessary to determine a species' status and distribution.
Habitat loss is driving the extirpation of fauna across Earth. Many species are now absent from vast areas where they once occurred in inhabited continents, yet we do not have a good understanding of the extent to which different species have been extirpated, nor the degree to which range contractions and habitat loss has contributed to this local extirpation. Here, for the first time, we use a combination of scientific literature, historical sources, spatial data, and expert elicitation to map the past extent of potential habitats, and changes thereto, of 72 of Australia’s most imperilled terrestrial birds. By comparing the area of potential habitat within the past and current ranges of these taxa, we quantify the extent over which each of Australia’s threatened terrestrial birds have likely been extirpated and assess the amount and configuration of potential habitat that remains. Our results show that since 1750 (before European colonization), at least one extant taxon of threatened bird has disappeared from over 530 million hectares (69%) of Australia, through both range contractions and loss of potentially suitable habitat (noting these are not mutually exclusive phenomena). Ten taxa (14%) have likely been extirpated from >99% of their past potential habitat. For 56 taxa (78%), remaining habitat within their current potential habitats has become fragmented. This research paints a sobering picture of the extent of local extirpation of threatened birds from much of Australia over a 250-year time period. By mapping and quantifying this loss, these findings will help refine scientific understanding about the impact of habitat removal and other pervasive threats that are driving this observed extirpation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.