To detect deviations, compare what you see, hear and smell today against your baseline in four categories: absent sounds, new sounds, new smells and visual changes. One deviation is a reason to watch closely and note it. Several that point the same way, or one that is fresh and close, are a reason to move away from the source and warn your group.
Part of Situational Awareness
Once a baseline exists, deviations fall into four categories: absent sounds, new sounds, new smells and visual changes. The parent article lists examples of each.
Once You Have a Baseline, Deviations Stand Out
The parent article puts it simply: once you have a baseline, deviations jump out. It groups them in four categories.
- Absent sounds — a creek that stopped flowing, insects that went quiet.
- New sounds — engine noise, chopping, hammering, gunshots.
- New smells — wood smoke from a new direction, cooking food, diesel fuel, human waste.
- Visual changes — new tracks on a trail you walk daily, a branch that was intact yesterday and is now broken, items moved at a cache site.
Worked Example
Distance to a sound that follows a visible flash: sound travels at roughly 340 m/s, so 5 seconds between flash and sound gives 5 × 340 = 1,700 m. For a sound with no flash to time, use your estimate of direction and relative loudness from your sound map, not a number.
What You Need
- A baseline — for comparison.
- The same routine — same route, same times.
- A small scale of response — decide in advance how many deviations trigger which action.
Method: Compare, Count, Respond
Step 1: Compare At each check, ask of each category: is anything different from the record?
Step 2: Note Write the deviation, the time and the direction.
Step 3: Count and weigh One deviation: watch closely and keep the note. Two or more in the same direction, or one fresh and near: move away from the source, reduce your signature and brief the group.
Step 4: List alternatives Write two possible causes. See Environmental Anomalies.
Step 5: Verify from a distance Check again in an hour, or tomorrow. Persistence matters.
Common Mistakes
- Explaining it away — “just an animal” is the confirmation bias the parent article warns of. Investigate by observing, not by dismissing.
- Ignoring the absence — silence is a deviation.
- Responding to a single sign as if it were certain — keep the response in proportion.
What’s Next
- Learn next: Mental Conditioning — staying sharp enough to notice
- Combine with: Danger Indicators — what the deviations mean