Environmental correlates of activity and energetics in a wide-ranging social carnivore

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.

Energy landscapes of Kodiak brown bears: A comparison of accelerometer and global positioning system derived estimates

“…This nding was in contrast to Bryce et al (2022), who noted the energetic costs derived from accelerometers tted to wolves were on average 1.3 times higher than the GPS method. Discrepancies between our results and that of Bryce et al (2022) are likely due to differences in ecology between wolves and brown bears, and highlight the importance of species-speci c considerations when examining GPS-derived energetic expenditure. Our movement based energetic expenditures (2.7-8.9 J kg -1 s -1 ) were similar to ranges for grizzly bears in the Yellowstone ecosystem, with reported expenditure values of 3.0-10.6 J kg -1 s -1 (Carnahan et al 2021).…”

“…Consent for publication may only be suitable for comparisons of movement-based energy expenditure among individuals (Bryce et al (2022).…”

A Standardized Method for Experimental Human Approach Trials on Wild Wolves

“…Altering the time budgets from more profitable activities (foraging, resting) to increased vigilance after disturbance may have fitness costs (Ordiz et al, 2013). Therefore, quantifying how human activities can affect carnivore behavior, and the potential implications for energy budgets (e.g., Bryce et al, 2022), can elucidate the role of wilderness areas for large carnivore conservation (Gilroy et al, 2015).…”

Energy landscapes of Kodiak brown bears: A comparison of accelerometer and global positioning system derived estimates

“…Accelerometers are also data intensive due to their continuous high frequency measurements, making analysis computationally demanding. A GPS-derived measure of energy expenditure offers an alternative to study animal energetic ecology when accelerometer data may not be available (Carnahan et al 2021;Bryce et al 2022). We found that the GPS-derived estimates of MDEE were on average 1.6 times greater than the ACC method, displayed less overall variation and likely overestimated true energetic expenditure.…”

“…Carnahan et al 2021). However, this method cannot account for metabolic energy demands and may only be suitable for comparisons of movement-based energy expenditure among individuals(Bryce et al (2022).…”