# Animal BiotelemetryLatest Publications

272
(FIVE YEARS 128)

## H-INDEX

21
(FIVE YEARS 7)

2050-3385, 2050-3385

2022 ◽
Vol 10 (1) ◽
Author(s):
K. Nebiolo ◽
T. Castro-Santos
Keyword(s):

Abstract Introduction Radio telemetry, one of the most widely used techniques for tracking wildlife and fisheries populations, has a false-positive problem. Bias from false-positive detections can affect many important derived metrics, such as home range estimation, site occupation, survival, and migration timing. False-positive removal processes have relied upon simple filters and personal opinion. To overcome these shortcomings, we have developed BIOTAS (BIOTelemetry Analysis Software) to assist with false-positive identification, removal, and data management for large-scale radio telemetry projects. Methods BIOTAS uses a naïve Bayes classifier to identify and remove false-positive detections from radio telemetry data. The semi-supervised classifier uses spurious detections from unknown tags and study tags as training data. We tested BIOTAS on four scenarios: wide-band receiver with a single Yagi antenna, wide-band receiver that switched between two Yagi antennas, wide-band receiver with a single dipole antenna, and single-band receiver that switched between five frequencies. BIOTAS has a built in a k-fold cross-validation and assesses model quality with sensitivity, specificity, positive and negative predictive value, false-positive rate, and precision-recall area under the curve. BIOTAS also assesses concordance with a traditional consecutive detection filter using Cohen’s $$\kappa$$ κ . Results Overall BIOTAS performed equally well in all scenarios and was able to discriminate between known false-positive detections and valid study tag detections with low false-positive rates (< 0.001) as determined through cross-validation, even as receivers switched between antennas and frequencies. BIOTAS classified between 94 and 99% of study tag detections as valid. Conclusion As part of a robust data management plan, BIOTAS is able to discriminate between detections from study tags and known false positives. BIOTAS works with multiple manufacturers and accounts for receivers that switch between antennas and frequencies. BIOTAS provides the framework for transparent, objective, and repeatable telemetry projects for wildlife conservation surveys, and increases the efficiency of data processing.

2022 ◽
Vol 10 (1) ◽
Author(s):
Caleb M. Bryce ◽
Carolyn E. Dunford ◽
Anthony M. Pagano ◽
Yiwei Wang ◽
Bridget L. Borg ◽
...
Keyword(s):

Abstract Background Environmental conditions can influence animal movements, determining when and how much animals move. Yet few studies have quantified how abiotic environmental factors (e.g., ambient temperature, snow depth, precipitation) may affect the activity patterns and metabolic demands of wide-ranging large predators. We demonstrate the utility of accelerometers in combination with more traditional GPS telemetry to measure energy expenditure, ranging patterns, and movement ecology of 5 gray wolves (Canis lupus), a wide-ranging social carnivore, from spring through autumn 2015 in interior Alaska, USA. Results Wolves exhibited substantial variability in home range size (range 500–8300 km2) that was not correlated with daily energy expenditure. Mean daily energy expenditure and travel distance were 22 MJ and 18 km day−1, respectively. Wolves spent 20% and 17% more energy during the summer pup rearing and autumn recruitment seasons than the spring breeding season, respectively, regardless of pack reproductive status. Wolves were predominantly crepuscular but during the night spent 2.4 × more time engaged in high energy activities (such as running) during the pup rearing season than the breeding season. Conclusion Integrating accelerometry with GPS telemetry can reveal detailed insights into the activity and energetics of wide-ranging predators. Heavy precipitation, deep snow, and high ambient temperatures each reduced wolf mobility, suggesting that abiotic conditions can impact wolf movement decisions. Identifying such patterns is an important step toward evaluating the influence of environmental factors on the space use and energy allocation in carnivores with ecosystem-wide cascading effects, particularly under changing climatic conditions.

2021 ◽
Vol 9 (1) ◽
Author(s):
Colin P. Gallagher ◽
Luke Storrie ◽
Michael B. Courtney ◽
Kimberly L. Howland ◽
Ellen V. Lea ◽
...
Keyword(s):

Abstract Background We report compelling evidence suggesting a predation event of a pop-up satellite archival tagged anadromous Dolly Varden (Salvelinus malma) by a marine mammal during summer in the Beaufort Sea based on abrupt changes in temperature and vertical movements. This observation provides insight on predator avoidance behaviour by Dolly Varden and the predator’s feeding frequency while the tag was ingested. Based on published distribution and ecology information, we presumed the predator was a beluga whale (Delphinapterus leucas). Supplemental satellite telemetry data from previously tagged Dolly Varden and beluga whales were used to determine the extent of spatial and vertical overlap between species in the area where predation occurred. Results Prior to the predation event, depths and temperatures occupied by the tagged Dolly Varden averaged 1.1 m and 3.1 °C, respectively. On July 7, 2020, depths remained shallow apart from a sudden dive to 12.5 m (16:45 UTC) followed by a precipitous increase in temperature from 4.4 to 27.1 °C (16:52 UTC) suggesting predation by an endotherm. Subsequent readings indicated the endotherm had a resting stomach temperature of 36.1 °C. Including the predation event, eight separate feeding events were inferred during the 20-h period the tag was ingested (before presumed regurgitation) based on subsequent declines in stomach temperatures (mean decline to 31.1 °C) that took an average of 24.1 min to return to resting temperature. The predator occupied mainly shallow depths (mean = 2.3 m), overlapping with tagged belugas that spent 76.9% of their time occupying waters ≤ 2.5 m when frequenting the area occupied by tagged Dolly Varden in the Canadian Beaufort Sea in July. Back-calculation based on tag drift and mean displacement by tagged belugas indicated the predation likely occurred west of the Mackenzie Delta. Conclusion Our findings provide new information on both anti-predator behaviour by, and marine predators of, Dolly Varden in the Beaufort Sea. We provide the first estimate of feeding frequency and stomach temperature recovery in a presumed wild beluga, and evidence for shallow foraging behaviour by belugas. Elucidating the likely predator and exploring the extent of overlap between Dolly Varden and beluga whales contributes towards knowledge on the trophic interactions in the Beaufort Sea.

2021 ◽
Vol 9 (1) ◽
Author(s):
Eleanor R. Dickinson ◽
Philip A. Stephens ◽
Nikki J. Marks ◽
Rory P. Wilson ◽
David M. Scantlebury
Keyword(s):

AbstractThe energy used by animals is influenced by intrinsic (e.g. physiological) and extrinsic (e.g. environmental) factors. Accelerometers within biologging devices have proven useful for assessing energy expenditures and their behavioural context in free-ranging animals. However, certain assumptions are frequently made when acceleration is used as a proxy for energy expenditure, with factors, such as environmental variation (e.g. ambient temperature or slope of terrain), seldom accounted for. To determine the possible interactions between behaviour, energy expenditure and the environment (ambient temperature and terrain slope), the rate of oxygen consumption ($${\dot{\text{V}}\text{O}}_{2}$$ V ˙ O 2 ) was measured in pygmy goats (Capra hircus aegarus) using open-flow indirect calorimetry. The effect of temperature (9.7–31.5 °C) on resting energy expenditure was measured. The relationship between $${\dot{\text{V}}\text{O}}_{2}$$ V ˙ O 2 and dynamic body acceleration (DBA) was measured at different walking speeds (0.8–3.0 km h−1) and on different inclines (0, + 15°, − 15°). The daily behaviour of individuals was measured in two enclosures: enclosure A (level terrain during summer) and enclosure B (sloped terrain during winter) and per diem energy expenditures of behaviours estimated using behaviour, DBA, temperature, terrain slope and $${\dot{\text{V}}\text{O}}_{2}$$ V ˙ O 2 . During rest, energy expenditure increased below 22 °C and above 30.5 °C. $${\dot{\text{V}}\text{O}}_{2}$$ V ˙ O 2 (ml min−1) increased with DBA when walking on the level. Walking uphill (+ 15°) increased energetic costs three-fold, whereas walking downhill (− 15°) increased energetic costs by one third. Based on these results, although activity levels were higher in animals in enclosure A during summer, energy expenditure was found to be significantly higher in the sloped enclosure B in winter (means of enclosures A and B: 485.3 ± 103.6 kJ day−1 and 744.5 ± 132.4 kJ day−1). We show that it is essential to account for extrinsic factors when calculating animal energy budgets. Our estimates of the impacts of extrinsic factors should be applicable to other free ranging ungulates.

2021 ◽
Vol 9 (1) ◽
Author(s):
Yulong Kuai ◽
Natalie V. Klinard ◽
Aaron T. Fisk ◽
Timothy B. Johnson ◽
Edmund A. Halfyard ◽
...
Keyword(s):

Abstract Background The successful use of acoustic telemetry to detect fish hinges on understanding the factors that control the acoustic range. The speed-of-sound in water is primarily a function of density, and in freshwater lakes density is primarily driven by temperature. The strong seasonal thermal stratification in the Great Lakes represent some of the steepest sound speed gradients in any aquatic system. Such speed-of-sound gradients can refract sound waves leading to greater divergence of acoustic signal, and hence more rapid attenuation. The changes in sound attenuation change the detection range of a telemetry array and hence influence the ability to monitor fish. We use 3 months of data from a sentinel array of V9 and V16 Vemco acoustic fish tags, and a record of temperature profiles to determine how changes in stratification influence acoustic range in eastern Lake Ontario. Result We interpret data from an acoustic telemetry array in Lake Ontario to show that changes in acoustic detection efficiency and range correlate strongly with changes in sound speed gradients due to thermal stratification. The steepest sound speed gradients of 10.38 m s−1/m crossing the thermocline occurred in late summer, which caused the sound speed difference between the top and bottom of the water column to be greater than 60 m/s. V9 tags transmitting across the thermocline could have their acoustic range reduced from > 650 m to 350 m, while the more powerful V16 tags had their range reduced from > 650 m to 450 m. In contrast we found that when the acoustic source and receiver were both transmitting below thermocline there was no change in range, even as the strength of sound speed gradient varied. Conclusion Changes in thermal stratification occur routinely in the Great Lakes, on timescales between months and days. The acoustic range can be reduced by as much as 50% compared to unstratified conditions when fish move across the thermocline. We recommend that researchers consider the influences of thermal stratification to acoustic telemetry when configuring receiver position.

2021 ◽
Vol 9 (1) ◽
Author(s):
Jinhong Luo ◽
Stefan Greif ◽
Huan Ye ◽
Sara Bumrungsri ◽
Ofri Eitan ◽
...
Keyword(s):

Abstract Background Bats are remarkable in their dynamic control over body temperature, showing both hypothermia with torpor and hyperthermia during flight. Despite considerable research in understanding bats’ thermoregulation mechanisms, knowledge on the relationship between flight and body temperature in bats remains limited, possibly due to technological restraints. Results We used onboard dataloggers including a temperature sensor and an inertial sensor (accelerometers) and continuously recorded the flight behavior and skin temperature (Tsk) subcutaneously of a perch-hunting bat, Hipposideros armiger, both in the laboratory and in the field. We provide evidence that flight increases the body temperature of bats. The median of the maximum increase in the Tsk caused by flight bouts was 3.4 °C (between 1.9 and 5.3 °C for different individuals) in the laboratory. The maximum Tsk for the bats was narrowly centered around 40 °C (between 38.5 and 40.9 °C). Moreover, we found that the faster the Tsk rises, the greater the maximum increase in Tsk. Interestingly, bats can slow down the Tsk rises with intermittent fights, during which they perch after brief flight bouts to allow the body temperature to drop rapidly. Similar data were collected from field recordings in free-ranging bats. Conclusions We suggest that perch-hunting behavior observed in approximately 200 species of bats that results in intermittent flights may function as a thermoregulatory strategy, in addition to optimizing energy efficiency as demonstrated by previous studies.

2021 ◽
Vol 9 (1) ◽
Author(s):
Mason R. Cole ◽
Jenifer A. Zeligs ◽
Stefani Skrovan ◽
Birgitte I. McDonald
Keyword(s):

AbstractDetecting when and where animals feed is key to understanding their ecophysiology, but our ability to collect these data in marine mammals remains limited. Here, we test a tag-based accelerometry method to detect prey capture in California sea lions. From synchronized underwater video and acceleration data of two trained sea lions, we isolated a combined acceleration and Jerk pattern that reliably indicated prey capture in training datasets. We observed a stereotyped feeding motion in underwater video that included (1) mouth opening while approaching prey; (2) head deceleration to allow initial suction or prey engulfment, and (3) jaw closure. This motion (1–3) was repeated if a prey item was not initially engulfed. This stereotyped feeding motion informed a signal pattern phrase that accurately detected feeding in a training dataset. This phrase required (1) an initial heave-axis Jerk signal surpassing a threshold based on sampling rate; (2) an estimated dynamic surge-axis deceleration signal surpassing −0.7 g beginning within 0.2 s of the initial Jerk signal; and (3) an estimated dynamic surge-axis acceleration signal surpassing 1.0 g within 0.5 s of the beginning of the prior deceleration signal. We built an automated detector in MATLAB to identify and quantify these patterns. Blind tests of this detector on non-training datasets found high true-positive detection rates (91%–100%) with acceleration sampled at 50–333 Hz and low false-positive detection rates (0%–4.8%) at all sampling rates (16–333 Hz). At 32 Hz and below, true-positive detection rates decreased due to attenuation of signal detail. A detector optimized for an adult female was also accurate at 32–100 Hz when tested on an adult male’s data, suggesting the potential future use of a generalized detector in wild subjects. When tested on the same data, a published triaxial Jerk method produced high true-positive detection rates (91–100%) and low-to-moderate false-positive detection rates (15–43%) at ≥ 32 Hz. Using our detector, larger prey elicited longer prey capture duration in both animals at almost all sampling rates 32 Hz or faster. We conclude that this method can accurately detect feeding and estimate relative prey length in California sea lions.

2021 ◽
Vol 9 (1) ◽
Author(s):
Richard M. Gunner ◽
Mark D. Holton ◽
David M. Scantlebury ◽
Phil Hopkins ◽
Emily L. C. Shepard ◽
...
Keyword(s):

Abstract Background Understanding what animals do in time and space is important for a range of ecological questions, however accurate estimates of how animals use space is challenging. Within the use of animal-attached tags, radio telemetry (including the Global Positioning System, ‘GPS’) is typically used to verify an animal’s location periodically. Straight lines are typically drawn between these ‘Verified Positions’ (‘VPs’) so the interpolation of space-use is limited by the temporal and spatial resolution of the system’s measurement. As such, parameters such as route-taken and distance travelled can be poorly represented when using VP systems alone. Dead-reckoning has been suggested as a technique to improve the accuracy and resolution of reconstructed movement paths, whilst maximising battery life of VP systems. This typically involves deriving travel vectors from motion sensor systems and periodically correcting path dimensions for drift with simultaneously deployed VP systems. How often paths should be corrected for drift, however, has remained unclear. Methods and results Here, we review the utility of dead-reckoning across four contrasting model species using different forms of locomotion (the African lion Panthera leo, the red-tailed tropicbird Phaethon rubricauda, the Magellanic penguin Spheniscus magellanicus, and the imperial cormorant Leucocarbo atriceps). Simulations were performed to examine the extent of dead-reckoning error, relative to VPs, as a function of Verified Position correction (VP correction) rate and the effect of this on estimates of distance moved. Dead-reckoning error was greatest for animals travelling within air and water. We demonstrate how sources of measurement error can arise within VP-corrected dead-reckoned tracks and propose advancements to this procedure to maximise dead-reckoning accuracy. Conclusions We review the utility of VP-corrected dead-reckoning according to movement type and consider a range of ecological questions that would benefit from dead-reckoning, primarily concerning animal–barrier interactions and foraging strategies.

2021 ◽
Vol 9 (1) ◽
Author(s):
Michelle Modest ◽
Virginia Andrews-Goff ◽
William Gough ◽
David Johnston ◽
...
Keyword(s):

Abstract Background Despite exhibiting one of the longest migrations in the world, half of the humpback whale migratory cycle has remained unexamined. Until now, no study has provided a continuous description of humpback whale migratory behavior from a feeding ground to a calving ground. We present new information on satellite-derived offshore migratory movements of 16 Breeding Stock G humpback whales from Antarctic feeding grounds to South American calving grounds. Satellite locations were used to demonstrate migratory corridors, while the impact of departure date on migration speed was assessed using a linear regression. A Bayesian hierarchical state–space animal movement model (HSSM) was utilized to investigate the presence of Area Restricted Search (ARS) en route. Results 35,642 Argos locations from 16 tagged whales from 2012 to 2017 were collected. The 16 whales were tracked for a mean of 38.5 days of migration (range 10–151 days). The length of individually derived tracks ranged from 645 to 6381 km. Humpbacks were widely dispersed geographically during the initial and middle stages of their migration, but convened in two convergence regions near the southernmost point of Chile as well as Peru’s Illescas Peninsula. The state–space model showed almost no instances of ARS along the migratory route. The linear regression assessing whether departure date affected migration speed showed suggestive but inconclusive support for a positive trend between the two variables. Results suggestive of stratification by sex and reproductive status were found for departure date and route choice. Conclusions This multi-year study sets a baseline against which the effects of climate change on humpback whales can be studied across years and conditions and provides an excellent starting point for the investigation into humpback whale migration.

2021 ◽
Vol 9 (1) ◽
Author(s):
Eirik Svendsen ◽
Finn Økland ◽
Martin Føre ◽
Lise L. Randeberg ◽