text: Appendix I
  smells odors from the ground and air and forms scent pictures. He puts together these scent pictures from
  several sources.
  Individual Scent
  I-32. This is the most important scent when it comes to tracking. Vapors from body secretions work
  their way through the evader's shoes onto the ground. Sweat from other parts of the body rubs off onto
  vegetation and other objects. Scent is even left in the air.
  Reinforcing Scent
  I-33. Objects that reinforce the scent as it relates to the evader are introduced to the dog. Some
  reinforcing scents could be on the evader's clothing or boots, or they could be made of the same material as
  is used in his clothing. Even the smell of boot polish can help a dog find a person.
  Ecological Scent
  I-34. For the dog, the most important scent comes from the earth itself. The strongest smell comes from
  disturbances in ecology such as crushed insects, bruised vegetation, and broken ground. Over varied
  terrain, dogs can smell particles and vapors carried by the evader wherever he walks.
  UNFAVORABLE TRACKING CONDITIONS
  I-35. Few conditions are ideal for dog tracker teams. During training, the teams learn the difficulties
  that they will face and develop skills to cope with them:
  Unverified Start Point
  I-36. The dogs may follow the wrong route or scent.
  Heat, Low Humidity, and Dry Ground
  I-37. These all cause rapid evaporation of scent.
  Wind
  I-38. Wind disperses scent, causing the dog to track downwind.
  Heavy Rain
  I-39. This washes scent away.
  Distracting Scents
  I-40. These divert the dog's attention from the trail. Some distracting scents are blood, meat, manure,
  farmland, and populated areas.
  Elements that Cover Scent
  I-41. Some elements in nature cover the scent picture partially or completely. For example, sand can
  blow over the tracks and help to disguise it; snow and ice can form over the track and make it nearly
  impossible to follow; and water can completely obscure a trail.
  FAVORABLE TRACKING CONDITIONS
  I-42. Some conditions favor the teams:
  Fresh Scent
  I-43. Scent is probably the most important factor for dog tracker teams. Fresh scent increases the
  chance of success.
  Verified Starting Point
  I-44. Introducing a definite scent to the dogs early on increases the chance that the dogs will follow the
  correct trail.