Fig. 1

Two models for estimating daily energy expenditure in meerkats. We developed two models to estimate DEE in meerkats. Both involve computing a linear ‘power calibration equation’ that converts vectorial dynamic body acceleration (\({a}_{d}\), in m/s²) to power in watts using allometric energy expenditure. We computed rate of energy expenditure during resting (\({\dot{E}}_{R}\), in W) using Eq. 1 [16], and that during locomotion (\({\dot{E}}_{L}\), in W) using Eq. 3 [17]. In ACTIWAKE (A), the waking and sleeping hours were treated separately. The power calibration equation was computed using locomotion data and applied during the waking period; the animal was assumed to be resting during the sleeping period. Daily energy expenditure (DEE) was computed as the sum of waking and sleeping energy expenditure. In ACTIREST24 (B), no distinction was drawn between the waking and sleeping hours. The power calibration equation was computed using both locomotion and resting data and applied to the entire 24-h period. Both A and B required information on locomotion speed. For this, we developed a new algorithm (Fig. 2) to infer speed from accelerometer, gyroscope, and behavioural annotation data. EE: energy expenditure