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 |