Straight and Narrow
These photos, also taken yesterday in the deep fresh snow, illustrate the lesson my girls - and other forest creatures - teach: take the path of least resistance.
I've watched them, numerous times, follow the narrow indentation left by the ski of a snowmobile, rather than the wider and more churned-up path left by the traction portion of the machine. This requires that their feet hit the snow in almost perfect single file, since the ski of the snowmobile leaves a trail perhaps four inches wide - too narrow for my feet! But I can tell, when I do run on these indentations, that the snow is packed harder and so supports weight better than the messier track where the traction portion of the machine has been.
I frequently see fox and coyote tracks following the ski's trail through the snow, up the road, until they veer off into the forest.
In these photos, you can see that the girls not only followed the ski tracks (despite being buried under 4-6" of fresh snow) but they also followed each other, maximizing the benefit. Smart girls. In the lower photo, my tracks are to the right of the narrow trail the girls made where the snowmobile ski had gone, and you can see faint indentations where other ski tracks were made the day before.