Figure 4
From: Characterization of lab-based swarms of Anopheles gambiae mosquitoes using 3D-video tracking
Differences in 3D velocities in male and female swarms. Graphs represent the probability distribution of the three components of the velocity and of the speed, for 19 male swarms and 11 female swarms. In both males (top row) and females (bottom row), we found mean values of vx, vy and vz close to 0, confirming the stable position in time of swarms at a group level. Top row: males. The narrow distribution of vy, i.e. the velocity component parallel to the direction of gravity, together with the double-peaked distributions of vx and vz, reveals that motion mainly occurs on the xz-plane. The distributions of vx and vz, with the two peaks at ± 0.5 m/s, further indicate the lack of any favoured direction of flight on the xz-plane, but rather, in the swarm all directions on the horizontal plane are explored with the same probability, i.e. a change in the vx, vz reference frame would display the same double-peaked distributions. Bottom row: females. Female motion is qualitatively distinct, with the distributions of the three components of the velocity and of the overall speed wider than in males. Females are more prone to move in the direction of gravity, with a vy distribution larger than males (std = 0.38 m/s against the std = 0.18 m/s that we found in males), and with the double peak of the distributions of vx and vz being barely visible.
