Fig 4. Attraction distance in μm (A) and mean speed in mm/s (B) of floral anthers produced by a metal hummingbird model with varied electrostatic charges (in pC).

Linear regressions as follows: Nicotiana glauca (red symbols, n = 10; distance = 18 + 0.07 × charge, p < 0.01; speed = 0.33 + 0.0006 × charge, p = 0.13), Hemerocallis sp. (green symbols, n = 5; distance = 35 + 0.13 × charge, p = 0.15; speed = -0.53 + 0.0044 × charge, p = 0.09), Penstemon sp. (blue symbols, n = 10; distance = 18 + 0.04 × charge, p = 0.08; speed = 0.03 + 0.0001 × charge, p = 0.26), Aloe arborescens (purple symbols, n = 10; distance = -17 + 0.17 × charge, p < 0.001; speed = -0.32 + 0.0026 × charge, p < 0.001).