How to most effectively use autonomous recording units when data are processed by human listeners

Description: This report assesses the most efficient means to maximize the extraction of information from audio recordings via human listening while minimizing listening cost. Using a variety of datasets, questions regarding optimization were addressed. Conclusions indicate that optimization depends on various factors such as the species of interest and the study objective. However, this report provides evidence for two general recommendations: 1) leave an audio recording unit for several days to detect species close to a recording unit and to increase the probability of detecting rarer species that are only periodically near a recording unit; and 2) listen to 1-minute time blocks within any longer time interval to provide greater flexibility in methods and the highest return on listening investment.