Key to Mammal Families

Each member of a mammal family tends to have a similar track pattern distinguished by the pattern of toes, structure of the heel pad, and other characteristics. The first step in track identification is to identify the family.

To narrow down the families, first determine which major group of patterns your track belongs to:

Four Toes

Four Front, Five Hind

Five Toes

Two Toes (hoofed)

Four Toes

Track Characteristics

The presence of claws is an obvious clue to the canines but beware that claws do not show in every track on some substrates. A more subtle clue is asymmetry, the left and right sides of canine tracks are nearly mirror images (symmetry) while feline tracks appear askew and have one toe clearly longer than the others like your own hand (asymmetry). The leading edge of a feline heel pad is usually lobed, a prominent feature in the bobcat and cougar examples below. The large hind feet of lagomorphs and bounding track pattern should be self-evident.

Examples

Canines

Five Toes

Track Characteristics

Pay particular attention to the complexity of heel pads in this group. Weasels have a number of pads arranged in an arc. Even when these are fused, as in the badger below, you can still see the parts. You can feel the lobing with your fingers in a track. Most rodents have a similar complex of small heel pads arranged differently than weasels. Raccoons and opossums have long digits so their tracks look much like a human hand. Raccoon digits are slightly bulbous. The opposing thumb of the opossum is unmistakable. Bears have simple heel pads and are, of course, much larger than the rest of the group.

Examples

Mustilids

Four Front and Five Hind

Track Characteristics

As a rule, rodents have 4 front toes and 5 hind toes. There are a couple exceptions (namely beaver, nutria, mountain beaver) with five front toes, though the fifth toe may not always show. The complex heel pad (several pads if various arrangements) is usually an important clue for rodents, though porcupines are oddballs. The aquatic species (muskrat, beaver, nutria) have noticeable webbing between the toes.

Examples

Two Toes (Hooves)

Track Characteristics

The two-toed ungulates superficially all look very similar and overlap considerably in size. For example, I will show you later that even though elk are clearly much larger on average than mule deer, there is sill much overlap in the size. However, attention to a few characteristics unique to hooves will help narrow the field.

Elk, for example, have a distinct rim around the edge of each clout (toe) known as the wall. The wall shows clearly in tracks and may be all that appears with a hard substrate. The small pad at the back of the clout gives way to the depressed subunguinus. This gives a distinctive hump in the track compared to deer where the pad covers most of the clout and leaves a flat bottomed track. Bison also have a prominent wall but the clout is very blunt, giving a squared off or round appearance. The pad extends further up the inside of the clout compared to elk.

Deer and elk have pointed toes that tend to nearly touch on firm ground. In contrast, the taper on the inside of the clouts for goats and pronghorn give the track a slighly spread look even when not splayed. See Halfpenny's books for more detail on clues for distinguishing ungulates.

Examples

Influence of Substrate

The substrate where tracks are laid influences the shape and distinctiveness of the track. Learn to look pick out the distinctive features of a track in different substrates. Some examples are:

Sand

Damp, fine sand records good detail. The disturbed sand around the track usually begins to dry first, making tracks easier to see. As the sand continues to dry, detail is lost. By the time the sand has dried completely, tracks have become very ambiguous.

Variablility in Nature

Most guide books give average track and gait measurements for each species. You can only use these as a relative guide, however. There is considerable variation in size within a species and overlap between similar species. Age and gender are two important determinants of size.

Comparison of Deer and Elk

In the figure below I plot the results of a little study comparing mule deer and elk tracks. Without going into detail about the study, let me use this to illustrate these two important lessons about variability.

Everyone who has seen an elk knows that they are on average much bigger than mule deer yet note that nearly one third of my elk sample (4 out of 13) overlapped with deer. Keep in mind that every animal was small once. I conducted the study during the fall so the smallest elk tracks were probably first year calves. The larger deer were probably bucks.

Other Sign

Good, clear tracks are usually the exception rather than the rule. The track evidence is often fragmentary. Fortunately animals leave many different types of sign. Some animals leave lots of sign but rarely any tracks. Thus a good tracker uses all available clues to piece together the story. Here are a few examples:

Tree Damage

Overview of Gaits

Here is a brief visual overview of the basic gait patterns you are likely to encounter. You will need to supplement this with live instruction and a good text (in particular see the books by James Halfpenny).

Diagonal Stride

Walk

In a diagonal stride, their are alternating left and right tracks--just like our own tracks except that most animals have four rather than two feet. The hind foot usually comes down directly on top of the track left by the front foot. This is called direct register. The diagonal stride is typical of all canines, felines, and ungulates.

Tracking Resources