Use of Acceleration and Acoustics to Classify Behavior, Generate Time Budgets, and Evaluate Responses to Moonlight in Free-Ranging Snowshoe Hares

Abstract

Technological miniaturization is driving a biologging revolution that is producing detailed and sophisticated techniques of assessing individual behavioral responses to environmental conditions. Among the many advancements this revolution has brought is an ability to record behavioral responses of nocturnal, free-ranging species. Here, we combine captive validations of acceleration signatures with acoustic recordings from free-ranging individuals to classify behavior at two resolutions. Combining these classifications with ∼2 month-long recordings, we describe winter time budgets, and responses of free-ranging snowshoe hares to changing moonlight. We successfully classified snowshoe hare behavior into four categories (not moving, foraging, hopping, and sprinting) using low frequency accelerometry, with an overall model accuracy of 88%, and acoustic recordings to three categories (silence, hopping, and chewing) with an accuracy of 94%. Broad-scale accelerometer-classified categories were composed of multiple fine-scale behavioral states with the composition varying between individuals and across the day. Time budgets revealed that hares spent ∼50% of their time foraging and ∼50% not moving, with most foraging and feeding occurring at night. We found that hares adjusted timing of activity in response to moon phase, with a 6% reduction in foraging and 30% reduction in traveling during the night when the moon was full. Hares compensated for this lost foraging time by extending foraging into the morning hours of the following day. Using two biologging technologies to identify behavior, we demonstrate the possibility of combining multiple devices when documenting behavior of cryptic species.

Optimisation of energetic and reproductive gains explains behavioural responses to environmental variation across seasons and years

“…Individual squirrels were captured on defended territories, weighed, assessed for reproductive condition, and fitted with an accelerometer (models Axy2/Axy3, 4 g [1.7% of body mass], Technosmart Europe) in collar form, either ventrally mounted on its own ( n = 128) or dorsally‐mounted in combination with a ventrally mounted VHF radio transmitter ( n = 361, model PD‐2C, 4 g [1.7% of body mass], Holohil Systems Limited, Carp, ON, Canada; see Studd, Landry‐Cuerrier, et al, 2019 for collar design). All accelerometers recorded acceleration between ± 8 g forces at a sampling rate of 1 Hz and temperature at a rate of 0.1 Hz, frequencies that have been shown to capture broad‐scale behaviour of small animals with high accuracy, allowing for long‐duration recordings (Tatler et al, 2018; Studd, Boudreau, et al, 2019). Squirrels were released at site of capture and remained free‐ranging until recaptured for collar removal (3–103 days later).…”

“…Meanwhile, consumer resource theory allows for behaviour to affect the consumption of resources, but treats energy expenditure as behaviourally independent (Yodzis & Innes, 1992; Post et al, 2000). The methodological constraint requiring direct observation of behaviour has now largely been eliminated by recent advances in biologging technologies which offer effective methods for continually recording fine‐scale behavioural variation (Kays et al, 2015) over long durations (Williams et al, 2016; Tatler et al, 2018; Studd, Boudreau, et al, 2019). Accordingly, we focus the next two paragraphs on describing an empirical approach for categorising behavioural variation and a conceptual approach to relating these behavioural categories to their energetic and ecological consequences.…”

Body temperature, heart rate, and activity patterns of two boreal homeotherms in winter: Homeostasis, allostasis, and ecological coexistence

“…Implants were set to record T b and heart rate once every 10 min, starting at least 12 hr post‐surgery, using 400 Hz ECG sampling frequency mode for hares and 700 Hz ECG sampling frequency mode for squirrels (based on the expected heart rate range of both species). All implanted animals were also outfitted with a radiocollar (VHF; Holohil) and accelerometer (attached to the collar; model Axy3, 4 g; Technosmart), which was set to record at 1 Hz with a resolution of ±8 g‐forces (as in Studd, Boudreau, et al, 2019; Studd, Landry‐Cuerrier, et al, 2019). All individuals were recaptured up to 80 days after the initial surgery (30 ± 17 days) to retrieve the collars, accelerometers and implanted dataloggers.…”

“…For simplicity, we only present results from day and night phases in the body of the paper, but have included a representative figure showing patterns during dawn and dusk phases in the Supporting Information (Appendix S1.5; Figure S2). The proportion of each phase of the day squirrels and hares spent active was classified from accelerometer data using hierarchal decision trees of acceleration thresholds provided in Studd, Landry‐Cuerrier, et al (2019); squirrels) and Studd, Boudreau, et al (2019); hares; more detail in Appendix S1.6).…”

Use of a Tri-Axial Accelerometer Can Reliably Detect Play Behaviour in Newborn Calves

“…Accelerometer technology has been utilised to monitor different behaviours in a wide variety of wild and domestic species including cattle [19,[25][26][27][28][29]. Accelerometers have been evaluated as tools for identifying many different types of bovine behaviour including lying behaviours [30][31][32][33][34][35], locomotion [34,36,37], feeding/drinking behaviours [35,[38][39][40] and play behaviour [41,42].…”