September 09, 2015
Unpredictable thermals or changing winds have likely resulted in more foiled big-game stalks than any other factor. Broken, highly-varied Southwestern terrain, combined with wildly-fluctuating temperatures, compounds this problem.
Successful hunters in the Southwest make a study of isolating (even anticipating), how terrain, weather and temperature changes affect prevailing breezes.
This is especially important when bowhunting, and endeavors such as dogging traveling, bugling elk. Every canyon or ridge traversed, every hour passed, can drastically alter your approach in relation to the wind. There are certainly factors beyond your control, but heeding the following rules will help minimize how many of your stalks end badly.
Cool air flows downhill. Warm air pushes uphill. Shade typically equals cool, while direct sunshine equates to warmth. That is the basis for everything to follow.
During cooler nighttime, early morning and post-sunset hours (under calm weather conditions) any game standing directly below you will likely receive your scent. When sun warms the earth, any game standing directly above you is in a position to catch your scent.
I prefer the term "Flow" in relation to thermals and breezes, as atmosphere acts like water while interacting with landscape. Hold that thought€¦
More problematic is that any larger piece of terrain can present conflicting, simultaneous thermal conditions. Let's say, for instance, a big muley or bugling elk crosses a heavily-wooded, shaded canyon head late in the morning.
Thermals are dropping solidly downhill. After another 100 yards that animal crosses a sunny face. Breezes will suddenly do a turnabout. Furthermore, at the seams of those distinct flow patterns are confusing swirls.
Working The 180
Another trap is the transition between, say, morning cool or evening heat, and warming morning or cooling evening temperatures.
At some point in that transition thermals will conduct a complete 180-degree shift.
In the Southwest where I've hunted most in New Mexico's Gila and Arizona's White Mountain regions,this occurs anytime between 8:30 and 10:30 a.m. on an average morning, and sometime around sunset in the evenings.
Closing the gap on game during the transition muddle is dicey, at best, requiring more intuitive instinct and forethought.
Stalking animals immediately after dawn, or shortly after sunset — perhaps the most predictable time, as temperatures can only move in one direction — offers the most honest winds. The long hours between these predicable timeframes is when things generally turn trickier.
The savvy hunter constantly evaluates terrain while moving, attempting to anticipate wind changes before committing to any critical move during a stalk.
Experience begins to make the hunch more reliable, but more often successful hunters simply avoid the gamble, backing out, circling and starting again. Scenarios are as varied as the terrain itself, but let's examine a couple examples.
A bugling bull elk moves off a sunny mesa, cutting off the edge in search of a bed on a shady-cool, north-facing slope. The wind that has remained steady in your face across the wide top becomes less stable.
As you descend deeper into cool shade, the air suddenly drops like a stone. If you've failed to anticipate this change, you've just blown it and given that bull your scent.
Likewsie, if you've stalked a feeding mule deer buck up a wide, meadow-like alpine bowl spilling off ragged peaks; the breezes in that cool bottom curling back your eyelashes steadily despite the late hour.
As the morning progresses rising temperatures coax the buck to climb out of the bowl and cross a ridge enroute to shade.
As he climbs he reaches an open, rocky crest and thermals do an about face. If you have followed directly uphill, you're busted.
Working The Eddies
Wind changes can also prove more subtle, even highly isolated in the form of micro-swirls. Let's say you've finally closed the distance on a feeding Coues whitetail, playing it safe, hanging back while awaiting an opportunity to gain the last 25 yards needed for a viable shot.
The buck drops into a small canyon head and you're temporarily screened. You seize the opportunity, hurrying to the upper lip of the header.
A front has been pushing wind across the ridge face, but as you peek into that header that once-steady breeze has curled back on itself, like a breaking ocean wave.
For just a moment the buck gets a whiff. It's not much, but it's just enough.
Bottoms and canyon heads often create these swirl traps, honest wind suddenly turning back on itself in an isolated vortex, perhaps only briefly, but just long enough to finish you off.
Think Of Air Like Flowing Water
As a dedicated fly fisherman I envision air currents in terms of flowing water. The midstream rock (or ridge point) affects steady downstream water flow in the form of an easily-observed back-eddy. The stump protruding from the bank of an otherwise smooth run (a rock point) creates a tiny whirlpool.
The underwater drop-off (a cliff lip) causes water to curl under itself. Making atmosphere visible, if only in your mind, makes it easier to anticipate potential wind traps.
Part of successfully stalking game is not only stealthily closing the distance, but doing so when breezes or thermals are to your advantage, hanging back and avoiding potential traps, then pouncing when all systems are go.
Remember, too, while the standard wind-in-your-face approach is certainly ideal, it isn't absolutely mandatory. Side-winds are just as viable, and in certain situations, preferred. They provide a bit more leeway to unexpected swirls or vertical, transitional thermal shifts.
Keeping tabs on wind is obviously a huge part of this. I use plastic squeeze bottles with flip-up dispensers, filled with powdered chalk or puff-ball mushroom spores. Milkweed or cattail fluff is also excellent.
The successful stalker checks the wind obsessively.
Avoiding wind traps certainly requires effort. Circling to avoid a trap can mean backing off and jogging around an entire ridge point; running down a canyon bottom only to trudge uphill again from a safe distance; side-hilling or ridge running to cut off animals traveling a canyon bottom.
This can come at the risk of losing contact with our target animal, but you are still in the game.
Let them catch your scent, and you've likely lost that animal completely.