Fig. 3.

Worked example 1: Difference in variability between the MAU duration, the gesture action duration, and the full gesture duration. Note. Boxplots of the gesture actions ‘beckon’ (n = 26), ‘raise’ (n = 54), and ‘reach’ (n = 85) showing the difference in duration variability between the A Minimum action unit (MAU) phase of a gesture action (MAU duration median for ‘beckon’ = 0.74 s (range = 0.26–1.75 s); for ‘raise’ = 0.82 s (range = 0.25–3.48 s); and for ‘reach’ = 0.76 s (range = 0.30–1.90 s; MAU duration mean for ‘beckon’: 0.74 s (SD = 0.37); for ‘raise’ = 0.91 s (SD = 0.60); and for ‘reach’ = 0.79 s (SD = 0.35)), B the time taken to produce and maintain the gesture action (Gesture action (GA) phase of a gesture action: GA duration median for ‘beckon’ = 0.81 s (range = 0.26–2.3 s); for ‘raise’ = 1.34 s (range = 0.37–12.64 s); and for ‘reach’ = 1.18 s (range = 0.35–5.04 s); GA duration mean for ‘beckon’: 0.95 s (SD = 0.48); for ‘raise’ = 2.55 s (SD = 2.75); and for ‘reach’ = 1.36 s (SD = 0.87)) and C including the recovery phase of the gesture (Full gesture duration median for ‘beckon’ = 1.00 s (range = 0.44–2.67 s); for ‘raise’ = 1.90 s (range = 0.44–12.64 s); and for ‘reach’ = 1.58 s (range = 0.53–6.10 s); Full gesture duration mean for ‘beckon’: 1.17 s (SD = 0.51); for ‘raise’ = 2.87 s (SD = 2.82); and for ‘reach’ = 1.84 s (SD = 1.02)). Species = Gorilla beringei beringei; n = 165 instances of gesture use, n = 26 signallers, filtered from data of mountain gorilla gestural behaviour collected on four social units (Mukiza, Oruzogo, Kyagurilo, Bitukura) in Bwindi Impenetrable National Park, Uganda, between 2019-2022 – data in ESM: Worked_example_1_data.csv)