DOI: 10.5061/dryad.017v9
title: Data from: Evaluation of an acoustic telemetry transmitter designed to identify predation events

description: The field of acoustic telemetry has evolved rapidly and now permits the
 remote sensing of animal behaviour, movement, physiology and survival in
 environments and species not previously possible. However, an inability to
 detect when a telemetered animal is consumed by a predator can complicate
 accurate interpretation of telemetry data. Here, we describe efforts to
 test two generations of a novel prototype acoustic telemetry transmitter
 designed specifically to detect predation. Testing involved either staged
 predation events where tagged prey (Rainbow Trout Oncorhynchus mykiss and
 Yellow Perch Perca flavescens) were fed to captive Largemouth Bass
 Micropterus salmoides, or false positive testing where prey fish were
 tagged and held without risk of predation. Metrics of interest were (a)
 the rate of correctly identifying predation events, (b) signal lag (i.e.
 the time required to detect a predation event), (c) tag retention time in
 the predator's gut, and (d) the rate of false positive triggering in
 both live and dead prey fishes. Staged predation events were successfully
 identified in 61/65 and 52/55 trials for generation 1 and 2 tags,
 respectively. Signal lag time was reduced in generation 1 tags (generally
 between 1 - 9 hours) relative to generation 2 (3 - 29 hours); although
 signal lag was highly variable. A generalized linear mixed model indicated
 strong evidence that signal lag and tag retention were both negatively
 correlated with water temperature, but were not affected by prey species
 and only slightly by individual predator traits. There was preliminary
 evidence that prey size may be an important determinant of both signal lag
 and tag retention. False positives in live fish were absent after 120 days
 for generation 1 tags (n=31), however rates were significantly higher
 (10/44) after only 66 days for generation 2 tags. False positives in dead
 fish suggested that 20% of generation 2 predation tags would falsely
 trigger 2-3 days post-mortem. Testing of the novel predation tags was
 encouraging however further testing is recommended. Predation tags will be
 an important contribution to the field of acoustic telemetry; permitting
 improved data interpretation and less subjective estimates of predation
 rates in biotelemetry studies.
description: Signal lag
 dataSignal lag data for
 predation tag testing. Indicates time between consumption of the tag and
 the first detected transmission in the 'post-predation' state.
 PRED = Individual Largemouth Bass,TAG_ID_BEF = Acoustic Tag ID before
 predation. All length measurements in mm, weights in
 grams.Lag_data.csvTag Retention DataTag retention data for predation tag transmitters. Represents the time from the predation event until the tag was evacuated from the predator (Largemouth Bass). PRED = Individual Largemouth Bass,TAG_ID_BEF = Acoustic Tag ID before predation. All length measurements in mm, weights in grams.Retention_data.csvR-script for analysis of signal lag dataR-script for analysis of signal lag data.Halfyard_et_al_LAG_Dryad_FINAL.RR-script for analysis of predation tag retention dataR-script for analysis of predation tag retention data.Halfyard_et_al_RET_Dryad_FINAL.RSummarized False Positive DataSummarized_False_Positive_Data.csv