Fig. 2From: Age related decline in female lar gibbon great call performance suggests that call features correlate with physical conditionComparisons of great call parameters between young adults (white bars) and old adults (gray bars). The overall call quality index (f) summarizes rankings derived from four parameters: delta F0 (a), maximum F0 (b), duty cycle (c) and number of high notes (d). Error bars represent ± 1 SEM. *P < 0.05, ***P < 0.001, NS: not significantBack to article page