Track Scene Investigation


TSI issues professional-level reports that may be used to verify the presence of rare mammal species, to clarify predation events, to find lost pets, to elucidate Endangered Species Act requiements, and to support section 7 managment consultations.  It is up to you to imagine how to use these reports.

The report will evaluate the quality of evidence for use in identification, and compare evidence to species-specific criteria we have defined.  Photographs or casts may be annotated to illustrate criteria.  The report will list criteria with a discussion of each as to its appropriateness and importance in making species determinations.

Below is a example in the form of  an abbreviated report to illustrate what your TSI report may look like. It illustrates the use of various clues to match criteria for species identification.  Marked up photos show the search for clues present in field evidence.(Click on the report below to view the PDF).

Photo Mark Ups

Photography, either on film or in digital format, captures details that even astute observers may missing in their field notes.  With modern photo processing these details may be enhanced to reveal information not initially apparent.  TSI analyses images to match clues to criteria for identification and behavior in footprints and trails.  Below are marked up photos that expose clues for the natural history detective.


Clues may be either qualitative or quatitative.  Footprints that appear similar qualitatively, such as a marten and a fisher, often need accurate measurements to differentiate.  Quality measurements must be made by minimum outline methods (see techniques section).  TSI may make up to 27 different measurements on the footprint of a five-toed animal with claws.

Once made, measurements can be compiled into tables to reveal species, age, and gender.  TSI has compiled such tables for many species, but because there are so many species, not all tables have large sample sizes.  Comparison of unknowns to these tables helps to finalize identification.

Below is an abbreviated table to illustrate the resultant information and how tables are derived.  Once the table is derived, two species are often compared using a cutoff diagram (below).  The cutoff diagram places a probability of species differentiation from a given clue, such as maximum diameter of scat.

Grizzly Footprint Cast

Casts and Photos

Nothing impresses a person more than the "touchy / feely" aspect of holding a real footprint cast in your hand.  Caressing a cast seems to bring the animal to life in your mind.  Sensitive finger tips can often reveal what the eye does not detect.

The Track Museum housing possibly the largest collection of plaster, foam, rubber, and plastics casts in the world.  The extent of our collections provides scope for evaluating variability in footprints.  Casts provide the ideal supplement to photos and measurements for identification work.

A Naturalist's World, parent company to TSI, produces plastic resin casts of real footprints of North American carnivores.  Please visit www.tracknature.com to purchase casts.  Additional casts are available by contacting Dr. Halfpenny at (406) 848-9458.  We can also provide copies of existing plaster casts from the museum when specific animals are needed.

Photographs of footprints, trails, signs, and track scene investigations are available by contacting Dr. Halfpenny at (406) 848-9458.

Cougar Footprint Cast     
Wolf Footprint Cast
  Black Bear Footprint Cast


Dr. Halfpenny has written many books and scientific articles dealing with a range of natural history and ecological subjects. Below is a bibliography of his manuscripts dealing mostly with tracking. Below are covers of many of his works dealing with tracking.

For the remainder of his writings go to www.Halfpenny.me. Go to the Publications tab to downolad many of his articles in PDF format. His books may be purchased though www.Tracknature.com. Go to the Books tab.


Click Here to Dowload PDF of Dr. Jim Halfpenny's Tracking Publications

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