The weather has been unusually cold and snowy for early November, and there have been days when conditions were perfect for seeing detail in the tracks of small animals–an icy base with about half an inch of new, soft snow on top. On one of those days I went to a location where I had seen flying squirrel trails in past years, and I found some 
beautifully detailed prints. In the photo on the right (direction of travel to the right), the right rear track is at the bottom of the frame, and the right front is just above it. The other two prints are at the top, the left rear just behind the left front. The toes and middle pads show up nicely in both front and rear tracks. The heels of the rear prints made impressions, and the paired heel pads of the right front track can also be seen.
Now compare the shot above with these chipmunk tracks, photographed on the same day and 
arranged almost identically except that the left front track is just below the left rear. There’s a similar amount of detail, with toes and middle pads clearly visible in both front and rear feet and the paired heel pads showing in both front feet. I had hoped that if I found really detailed tracks I would see features that would separate chipmunks and southern flying squirrels, but to my eyes there are no appreciable differences between the tracks in the two photos. The dimensions are similar as well: both sets of prints have a trail width (the distance from the right edge of the right rear print to the left edge of the left rear print) of 2 inches, and the length of the front track is 9/16 inch for the flying squirrel and 5/8 inch for the chipmunk, not significantly different. So how did I know that the tracks in the first photo were made by a southern flying squirrel, while those in the second belonged to a chipmunk?
The answer came from the differing trail patterns. 
Southern flying squirrels have flaps of skin (patagia) that connect the front and rear legs all the way out to the ankles, so they move differently from chipmunks (and also from tree squirrels, for that matter). The front tracks of a bounding southern flying squirrel are set almost as wide as the rear, and they are usually in front of, or occasionally between, the rear tracks. Because of the skin flaps, flying squirrels are not as fleet-footed on the ground as other small rodents, so their leaps are shorter. Compare the southern flying squirrel bounding trail in the photo above (traveling from bottom to top) with the next photo of a trail made by a chipmunk (traveling from top to bottom). 
In its normal traveling bound the chipmunk consistently places its rear feet ahead of its front, and its leaps can be much longer than those of the flying squirrel. Of course chipmunks do sometimes make short leaps, and they do sometimes place their front feet between (as in the second photo of the blog) or ahead of the rear. That kind of pattern in a chipmunk trail is an indication of a break in the rhythm, while it falls withing the normal bounding pattern for a southern flying squirrel. (By the way, neither of the bounding photos came from the day I took the close-up shots, but they illustrate the trail patterns I saw that day.)
More snow changes everything. All bounding animals switch to what I call a double-register bound when their feet sink deeply into the snow. The trail pattern consists of sets of two impressions more or less side-by-side, created when the rear feet come down in the holes just made by the front feet. 
For an animal the size of a flying squirrel even a few inches of soft snow can be enough to change its gait pattern from its normal bound to a double-register bound like the one in the photo at the right (direction of travel from lower right to upper left). The relative positions of front and hind prints no longer apply, but trail width can still be measured, and this trail had a trail width of 2 1/8 inches, squarely in the range for the southern flying squirrel. A chipmunk trail would have had a similar trail width, but the trail pictured above was made during a long stretch of cold weather. Chipmunks wait out winter’s coldest periods in a state of torpor in their underground refuges, while flying squirrels come out regularly even in frigid temperatures.
The mink is one of my favorite animals, so I’m always happy to find tracks like these, from a Tracking Club outing a few weeks ago. The marks made by the toes (5 on both front and rear feet) are small and oval or tear-drop shaped, and they form lopsided crescents around the middle pads. The claws may show as tiny pricks or as pointed extensions of the toes. The smallest toe lies on the inside of the track and farther back than the other toes, and it doesn’t always show. The mink that left these impressions was fidgeting around on a patch of stream side mud (the water is visible at the upper left) and the clear prints are mostly from the front feet.
Here are the two front and two rear tracks of a mink arranged in a pattern often seen in mink trails. The first track at the lower right is the right front, and the last one at the upper left is the left rear. In the center of the photo the left front is on the left and the right rear is on the right. The animal was loping from the lower right to the upper left, and the order of footfalls was right front, left front, right rear, left rear. 
A mink traveling 
on stream ice a few winters ago left a string of similar four-print patterns. In the center of each grouping the left front print is slightly behind instead of ahead of the right rear, but otherwise they’re a good match with the previous photo, with the same direction of travel and order of footfalls. Notice how the four-print groupings are separated by spaces with no tracks–a characteristic of lopes and gallops. When I see trails like this I can picture the mink doing its easy, ground-covering lope, its spine curving and extending with each landing and take-off. I couldn’t find a video of a loping mink that I liked, but I did find one of a fisher (closely related to the mink) doing the same gait. Watch it 
places for finding mink tracks, especially if there are roots or debris piles where prey animals can hide. The patch of sand visible in the center of this photo captured the tracks of a mink that was hunting in the surrounding tangle of logs and branches, deposited by a big flood several years ago.
But minks are resourceful when it comes to finding food. Last spring I was walking by an old log landing and I noticed a drying mud puddle. I’m always interested in mud so I went over to take a look, and to my surprise found mink tracks around the edges. There was a small pond nearby, but otherwise not much water, and I didn’t understand why this place–just a big area of bared mineral soil with a few mud puddles–would interest a mink. 
But the tracks were plentiful and very clearly mink. In the photo on the right the mink tracks run from lower left to upper right, and the big prints in the middle belong to my dog. As I moved around the edge and pondered, the mystery resolved itself. 
A leopard frog leaped from a grass clump into the water, then another one jumped, and then several more. Some enterprising mink had discovered the puddle, perhaps just as the tadpoles were transforming into frogs, and made use of the easy dinner. There were still plenty of frogs left to spend their summer feeding in the surrounding forest, overwinter deep in the soil, and then mate and lay eggs in the puddle next spring.