Figure 1.

Study species and study area. (a) Azure sand grasshoppers: the left individual was captured on the pale grey soil; the right individual was captured on the brown soil. Dark grey individuals (and all sorts of intermediates) also exist (figure 3a). (b) Aerial view of a small part of the study area, showing the proximity of the four different linear urban habitats (pavements) in-between large square areas containing natural brown, pale grey and some dark grey soils. (Online version in colour.)