At the animal tracking workshop we went to last week, we learned that when you are tracking, you should be looking at trail patterns rather than just individual tracks, because only then will you be able to measure stride (the measurement from tip of toe of one normal walking step to back of heel of the next successive step) and straddle (the measurement of the track patterns from one side to the other). This information will help you understand the size of the animal that made the tracks and the relative position of its hips and shoulders.
The mammals we were tracking had three kinds of stride: There were the walkers (dog family member, cat family), the waddlers (raccoons, skunks), and the hoppers (cottontails, jackrabbits). Let's see if I can illustrate what the patterns--not the tracks themselves--look like.
Tomorrow: Some great resources for learning about animal tracking