Behaviour, temperature and terrain slope impact estimates of energy expenditure using oxygen and dynamic body acceleration

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