34 
Psyche 
[March 
Wind velocity also affects abdomen dragging behavior. The mean 
wind velocity (measured every 15 seconds) and the wind velocity 
when the males initiate abdomen dragging were recorded for six 
different males (20 minutes of observation each; two 5 minute 
periods for determining mean wind velocity were alternated with 
two for measuring velocity at the initiation of abdomen dragging). 
For the total 120 minutes, the mean wind velocity was 34.3 
m/minute (S.D. = 32.5) while the mean wind velocity at the 
initiation of abdomen dragging was 60.1 m/ minute (N = 87; S.D. = 
27.5) (Figure 6). The means were significantly different (t-test, p < 
0.001). Using readings taken to find mean wind velocity as the 
expected values the distributions were shown to be significantly 
Figure 5. The effect of wind direction on position of the scent-marked plants for 
territory K (see Figure 2). Solid arrow indicates wind direction which on different 
days may come from different directions, Solid circles are plants not scent marked. 
Hollow circles are marked plants with the number of times it was marked in 10 
(above) and 15 (below) minutes. The ellipse is where the male perched on the 
sand. 
