Skip to main content

Table 4 Summary of assumed fate for each tagged yellow perch detected as predated

From: Identification of predation events in wild fish using novel acoustic transmitters

Tag ID Day of first predation detection Fate Justification
YP02 99 Predated Increase in spatial use following code switch then a detection pattern consistent with a predator-expelled tag after a gap in detections
YP10* 10 Predated Sudden increase in spatial use surrounding predation event and change in habitat use post-predation
YP12 55 Unclear—transmitter only Similar spatial use before and after code switch
YP17 71 Unclear—transmitter only Few post-predation detections, but 2 of 3 post-predation detections occurred on the same receiver months apart consistent with tag expelled from a predator. Since activity levels were low prior to predation, it is possible that this tag falsely triggered inside of a dead tagged fish. Post-predation detections would be removed by most false detection filters
YP19 88 Predated Reduced spatial use and detection pattern post-predation consistent with dropped tag. First post-predation detection occurs after a gap in detections, perhaps predated > 24 h before first post-predation detection
YP22* 18 Predated Clear change in habitat use
YP23* 1 Predated Predated soon after release. Tag is clearly dropped
YP26 32 Predated Decrease in spatial use change surrounding code switch. Few post-predation detections all on one receiver consistent with tag expelled from predator
YP33 24 Unclear—transmitter only Code switched after a gap in detections. Too few detections over a short period of time (4 days with detections across 24 days total)
YP34 2 Predated Increase in spatial use following code switch
YP38* 95 Predated No clear changes. Detections cease soon after tag triggers. Predator likely left study area
YP39* 94 Predated No clear spatial use changes but eventually detected as dropped
YP42* 3 Unclear—transmitter only Detected for 4 days total. Possibly a false positive, more likely a predation event soon after surgery and release when predator avoidance may have been hindered
YP43 37 Predated No clear change in spatial use but tag appears dropped across 5-month period
YP44 26 Predated Clear changes in spatial use and clear dropped tag across 5 months
YP47 29 Predated Sudden decrease in spatial use. Only 11 post-predation detections on 1 day
YP51 3 Predated Code switch soon after release. Clear dropped tag after 3-month gap in detections
YP52 2 Predated Code switched soon after release. Only ever detected on two receivers. Clear dropped tag after 3-month gap in detections
YP54 32 Predated No clear changes but movements sustained surrounding predation event, few post-predation detections but tag appears to have been expelled by predator
  1. Included are the Tag ID, the number of days post-release upon which the first post-predation signal occurred, the assigned fate based on tag and movement data, and the justification used for the classification. Focal individuals highlighted in Fig. 3 are marked with an asterisk