CONCLUSIONS
Because point counts survey sites differently than ARUs, their dual employment can identify situations where the performance of either method is strong or weak. When site visitation costs are shared, dual-method surveys are efficient and can markedly increase community coverage. We therefore recommend that, where possible, observer point counts be conducted when ARUs are deployed and when data are retrieved. Additionally, if some ARU recordings and point counts are conducted in tandem, point count data can be used to assess site-specific ARU detection radii (Van Wilgenburg et al., 2017; Yip et al., 2017). This would allow for better estimates of species densities from the audio data and help identify ARU species detection gaps (Vold et al., 2017). For occupancy studies, automated species detection software could then be used on longer sections of audio to efficiently search for species that have low ARU detection probabilities (Tegeler et al., 2012).
ACKNOWLEDGEMENTS
We thank C. L. Mahon and W. Easton (Environment and Climate Change Canada, ECCC) for generously loaning ARU units for the BC component of this study in 2019. We thank A. Edworthy, C. Rivas, T. White, and N. Froese for data collection and transcription. Fieldwork was supported by: a Werner and Hesse Wildegard Research award and the GoGlobal program at UBC to DRD, ECCC, a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant to KM, the Chilean Ministry of the Environment, and Comisión Nacional de Investigación Científica y Tecnológica (CONICYT, REDES150047 and FONDECYT de Inicio 11160932) to TAA and JTI. We thank BC Parks, the Chilean Forestry Service (11/2009 IX, 13/2015 IX, RNMCH 892127/2018) and The Huilo Huilo Biological Reserve for permission to collect data within public protected areas. TAA was supported by a Postdoctoral scholarship from CONICYT (74160073).
Data Accessibility. The datasets produced and analysed in this study are available at the Canadian Federal Open Government Portal [https://open.canada.ca/en/open-data; data DOI: to be assigned when deposited ]