Investigation of duty cycles in passive acoustic bat monitoring

Abstract

In long term data collection, sampling is a key parameter that can dictate the amount of data collected and also influence the available conclusions to be drawn. In the context of passive acoustic monitoring, recording an area’s soundscape at intervals (i.e., subsampling based on duty cycles) can alleviate data management costs, and has been widely investigated in the bird monitoring literature. However, the influence of duty cycle-based subsampling in passive acoustic monitoring of bats has not been thoroughly studied. Here, we discuss the effects of subsampling on ultrasonic recordings collected using AudioMoth recorders in the Union Bay Natural Area in 2022. We recorded continuously over the summer and then computationally applied duty cycles onto our data to generate subsampled data. The subsampled data was then fed into multiple bat call detection algorithms to understand the influence of different subsampling schemes. Our results show that subsampling schemes can impact the trends and activities that can be acoustically observed from echolocating bats. The results also show how the subsampling parameters may be tuned to collect valuable information while keeping data management costs low. We anticipate that this detailed investigation will aid in the design of efficient, long-term bat acoustic monitoring projects.

Aditya Krishna

Undergraduate Research Assistant

I am interested in studying echolocation as a sensing tool.