Wildlife Acoustic Sampling Techniques

Evaluation and Application of Acoustice Recording Systems for Surveying Wildlife

Four-channel soundscape recording system picture
Four-channel soundscape
recording system
for surveying birds
UltrasonicMicrophone1 picture
Ultrasonic Microphone

Technological advances have provided new tools for monitoring natural systems. One approach is the use of acoustic recordings for surveying animals, such as songbirds and bats. Acoustic recordings have numerous advantages, including minimizing observer errors (via single observer interpreting all recordings or cross-validation using multiple observers), sampling animals that are inherently difficult to capture or visually observe, creation of permanent records of surveys, and ability to incorporate field technicians with limited field identification skills. They often allow wildlife to be surveyed across a larger number of locations and much longer time periods (e.g., 24-hrs). As with any wildlife survey method, acoustic recordings have limitations, which need to be considered when designing and conducting wildlife studies. Limitations include greater time commitment, primarily in terms of processing acoustic recordings due to current performance of automated classification software, general inability to accurately estimate abundance, cost and maintenance of recording units, and comparability of data collected using different recording systems. I am collaborating with colleagues to test the effectiveness of acoustic recording technologies for sampling birds and bats. We have found that acoustic recording methods are able to perform as well or better than field observers in estimating animal occupancy patterns and abundance rates, particularly when combined with quantitative methods to account for imperfect detection probability. These studies are improving our knowledge of the limitations of acoustic recording technologies so that they can be properly implemented into wildlife research.

What we're working on:

  • Experimental evaluation of three acoustic recording systems for sampling bird communities using an automated playback system
  • Integration of acoustic recording and capture data into a multi-method occupancy modeling approach to quantifying bat habitat associations