8 NATURE-STUDY REVIEW [14:1— Jan., 1918 



The identification of the track requires a knowledge of the size 

 of the foot, kind of foot, methods of locomotion, and habits of the 

 different species. Mammals may be divided into three groups 

 according to their methods of walking. Most of the quadrupeds 

 walk on their toes with the heel raised from the ground and are 

 called digitigrade (Latin digitus, finger or toe + gradi, walk). 

 Others like the bear and man walk on the whole sole of the foot 

 with the heel touching the ground; mammals of this type are 

 called plantigrade (Latin planta, sole + gradi, walk). The third 

 group contains the hoofed animals like the horses and cattle. 

 These mammals walk upon their hoofs and are called unguligrade 

 (Latin ungula, hoof -f- gradi, walk). Many animals have feet that 

 are similar in shape but differ in size; those of the weasel for 

 example are about one inch in length whereas those of the wolverine 

 are five inches long. If we know this and carry a ruler with us 

 into the field the task of identification is not so great. If the 

 medium is favorable each toe leaves its own imprint as well as each 

 claw and we are thus enabled to learn how many toes the animal 

 possessed, a fact of some importance since the number in different 

 species is often different and the number may even differ on the 

 front and hind feet of a single individual. The claw marks are 

 indicators of the direction in which the animal was moving. The 

 illustrations show the tracks bf a few common species of mammals 

 and indicate how distinctive they really are. These illustrations 

 were copied from figures in Brunner's book on "Tracks and Track- 

 ing" with the permission of the Outing Co. It is extremely diffi- 

 cult, however, to distinguish between the tracks of certain species 

 whose feet and methods of locomotion are similar, or between the 

 males, females and young of a single species but difficulties of this 

 sort are. welcomed by the field naturalist since their solution is just 

 so much more pleasant. 



The tracks of a single individual differ according to the method of 

 locomotion while they were being made. The three common 

 methods are walking, trotting and galloping. This fact also adds 

 to the problems involved in the study of this subject. 



After the tracks have been identified we may go further in our 

 explorations and attempt to discover what the individual that made 

 the track was doing and what its mood was when the tracks were 

 made. Long distances between the impressions indicate that the 

 animal was moving rapidly. Speed most often indicates fear and 



