of an adult female Cougar, with penny for scale.
Trail characteristics: (1) The strides of females (measured from left hind track to left hind track, or right to right) average about 36 in. and the strides of males about 40 in. (Boone Smith, personal communication). (2) The width of walking trails is much wider in males than in females.
Elbroch has applied these same characters to other species, including Gray Foxes, Ringtails, Bobcats, American Minks, and Fishers. Preliminary results are very positive yet not so much so that we can say with certainty that they work all of the time. We encourage you to start gathering the data needed to develop these skills further, and the track and trail measurements from known-sex animals, so that we can begin to compile useful parameters for species in North America.
In hooved species, the relative weight difference between an individual animal's front and hind ends is proportional to the discrepancy in size between its front and hind tracks. In Bighorn Sheep and Mule Deer, where males are adorned with large horns or antlers, their front ends are much larger than their hind ends to support this additional weight; their feet and footprints reflect this discrepancy, and their front tracks are much larger than their hind ones. Female Bighorn Sheep and Mule Deer also have larger front tracks than hind tracks, but only slightly larger, and their front and hind tracks are much more similar in size. Females of both species carry their weight more evenly distributed between their front and hind ends than do their male counterparts. It is the larger difference between the length—and more often the width—of front and hind tracks of males that helps trackers determine an animal's sex. That difference in size between front and hind tracks of females is much smaller.
Carefully note the large disparity between the length and width of the front track above and hind track below in a mature Mule Deer buck.
The sexes may also be distinguished by association. The track of an adult in close association with a juvenile is probably that of a female with her young. Nursery herds may be identified by the presence of several young, or the absence of young may indicate a bachelor herd. When a species is gregarious, a solitary individual will probably be an adult male.
Determining the Relative Age of a Mammal
The relative age of an animal may be indicated by the size of the feet. The hooves of young deer will have sharper edges, while older individuals may have blunted hooves with chipped edges. Younger individuals with padded feet may have more rounded pads. Some animals have specific breeding periods. If it is known at what time of the year an animal is born and you know the relative growth rates for the species, a reasonably accurate estimate of a young animal's age can be made from the size of the track.
Here the larger track of the adult female Cougar on the left is easily differentiated from her five- or six-month-old kitten on the right. Through association, determining the sex of the adult is made easy, and with practice (and ample opportunity to see the animals responsible for making the tracks), determining the relative age of the younger animal from the size of its footprint is possible.
Track Patterns
Competent trackers complete two tasks in interpreting a series of animal tracks. First, they analyze the pattern of tracks on the ground so as to visualize how the animal was moving. Second, they interpret the behavior—the meaning in what they are seeing. The first task is more systematic and scientific, while the second is more speculative, relying more upon imagination. Let's take each in turn.
Gaits and Track Patterns
A gait describes the way in which an animal is moving; it is not a description of a specific track pattern. There will be numerous track patterns for each gait, depending upon the speed and behavior of the animal, as well as the anatomy and morphology of the species.
We must also be aware of the complications introduced by language differences. Trackers around the globe use different words to describe the same thing. Some people prefer words that describe track patterns on the ground, while others prefer terminology that describes the way an animal was moving (the gait). This book presents the vocabulary most widely accepted by trackers across the globe, and that which was used by Eadweard Muybridge (1957) in his pictorial presentation of Animals in Motion. This vocabulary provides you with visual information about how an animal is moving—which is crucial in envisioning and becoming that animal in advanced levels of tracking (Liebenberg 1990). But understand that no terminology is better than another. What's important when communicating with others about gaits and trails is that you are all envisioning the same motions.
Here we separate gaits into three categories:
1. Walks and trots in which the front feet fall at consistent, rhythmic distances from each other (created by keeping the spine straight and allowing the momentum to be driven by motion in the legs);
2. Lopes, gallops, hops, and bounds in which the front feet land in alternating short and long distances from each other (created by stretching and contracting the spine, in addition to moving the legs); and
3. Bipedal gaits in which animals move on only their hind legs.
Walks and Trots
Walking
Walking is a slow gait in which each foot moves independently, and at no point during a cycle of footfalls does the animal lose contact with the ground. We will arbitrarily begin with the right hind foot in our example. The right hind leg moves forward, and just before touching down, the right front lifts up and moves forward. For a moment, two feet are off the ground, and then the right hind touches down. The right front continues forward and then touches down. The left hind moves forward, and just before it touches down, the left front picks up and moves forward. For a second time in the cycle of footfalls there are only two feet in contact with the ground, and then the left hind touches down. The left front continues forward and then touches down. Immediately the cycle begins again, and the right hind picks up and moves forward. Rhythmically, this would sound like “1, 2, 3, 4, 1, 2, 3, 4, 1, 2….,” where each number is an independent footfall. Note that the rhythm is continuous—that is, without breaks or pauses.
A walking Polar Bear.
When an animal is walking, its hind foot may land in any relation to the front track made by the front foot on the same side of the body. Remember, the right front foot picks up and moves forward before the right hind foot touches down. For this reason, the hind foot may land exactly where the front foot had been placed—that is, atop the track made by the front foot, called a direct register—or even touch down beyond the front track, called an overstep.
A good portion of time during each cycle of footfalls, only one leg is lifted from the ground, which allows for three feet to support the animal while in motion. These three legs act similarly to the legs of a tripod, which is a sturdy arrangement that efficiently balances heavy objects, including wide animals with short legs.
Walking is common among almost all the animals. For many widebodied animals, such as beavers, porcupines, and bears, it is their most common method of moving. It is also the common gait for deer, elk, antelope, and all members of the cat family. Other species walk when exploring or while traveling in deep substrates, like snow, to save energy.
A variation of the walk is the stalk. In the stalk, only one limb moves at a time, but the order in which the feet move is the same as for the walk. The right hind foot moves forward and touches down. The right front foot moves forward and touches down. Then the same sequence occurs for the left hind foot, followed by the left front. The resulting trail is an understep walk, which means the hind tracks in each pair register behind the front tracks.
There are numerous variables to consider when interpreting speed from a series of tracks in a trail, but a general rule holds true for