re: Interesting.
The dust devils remove dust, exposing darker soil... So what you see is the accumulation of trails from hundreds of dust devils... What I find interesting is the landing site seems to be a localized area of dust devil activity- I see one possible reason for this, If you look at the trais the wind direction is clearly to the SE, Now, look jest NW of the trails, there is a darher colored area there- perhaps localized heating from the sun spawns the devils?
Dust devils have been caught in the act by MGS- go to APOD and search for dust devil/s