Field assessment of C‐ POD performance in detecting echolocation click trains of bottlenose dolphins ( Tursiops truncatus )

We evaluated the performance of dolphin echolocation detectors (C‐ POD s) in the New River, North Carolina, by ground‐truthing echolocation detections with digital acoustic recordings. We deployed C‐ POD s at three sites for a total of 204 monitoring hours. We also performed detection range trials at two sites where water depths ranged from 1.0 to 4.5 m. We used Detection Positive Minutes ( DPM s), minutes of C‐ POD recordings that contained at least one echolocation click train, to indicate the presence of at least one dolphin. The C‐ POD s performed well in detecting dolphin click trains, although all units performed conservatively by failing to detect some echolocation events and therefore underestimated the true occurrence of dolphins. C‐ POD s reported only a small number of false detections, as indicated by low false positive rates ranging between 1% and 4% for individual units. Overall, C‐ POD s performed with a high accuracy (72%–91%) and detected echolocation at a distance of at least 933 m. We conclude that C‐ POD s hold considerable promise in future monitoring studies of this species, but recommend a careful study design especially in complex, coastal environments.