Energy Expenditure of a Female Tiger in a Human-Altered Habitat: Insights From Tri-Axial Accelerometry.

Energy expenditure is central to animal ecology and shapes how individuals balance foraging, movement, thermoregulation and risk avoidance. Large carnivores, like tigers (Panthera tigris), face high energetic demands for territorial defence, hunting, competition and reproduction. These challenges further intensify in human-modified landscapes, where habitat fragmentation, prey depletion and human disturbance alter movement and behaviour. To quantify these dynamics at a fine scale, we used high-resolution tri-axial accelerometry to examine the energetic and behavioural patterns of a sub-adult female tiger in the human-dominated Brahmapuri Forest Division of the Eastern Vidarbha Landscape. The individual was fitted with a GPS collar equipped with an 8 Hz accelerometer, and Vectorial Dynamic Body Acceleration (VeDBA) was calculated as a proxy for energy expenditure. Behavioural states were classified using the Daily Diary Multi-Trace (DDMT) software, which implements a Boolean decision-tree framework, and validated using camera traps, field observations, and GPS-based cluster analyses. We further modelled diel and seasonal variation in energy expenditure across life stages (pre- and post-dispersal) using generalised additive models. Four behavioural states were identified: resting, walking, travelling and hunting. Resting dominated the activity budget (~65%), while travelling peaked in the evening (~58%). Energy expenditure (VeDBA) was higher during the post-dispersal phase (p < 0.001), reflecting increased movement likely associated with territory establishment and defence. Seasonal patterns varied by life stage: during pre-dispersal, winter and summer exhibited bimodal elevated energy expenditure at dawn and dusk, whereas monsoon showed a unimodal activity peaking in the evening, likely influenced by dense vegetation cover and localised resource distribution. Similar bimodal patterns persisted during the post-dispersal phase, with dawn energy expenditure lower during the monsoon, while dusk activity was similar across seasons. Our findings highlight the behavioural flexibility of a female tiger navigating a human-altered landscape and demonstrate the utility of accelerometry for quantifying fine-scale energetics.