How Humidity Affects Your Scent Control Strategy
March 09, 2015
Almost every whitetail hunter knows weather conditions can impact deer activity. Some of the hunts when I've seen the most deer active have been just before or just after a major change in the weather.
However, it seems few hunters consider how weather conditions impact the ability of deer to detect hunters. Most of us consider wind direction. We attempt to place our stands downwind of where we expect to see deer. However, there is another factor in addition to wind direction and speed that can be a big factor in whether we see deer from our stands.
The factor I am talking about is humidity. A simple definition of humidity, from Merriam Webster, is the "amount of water vapor in the air." But understanding relative humidity isn't quite that simple. If you want to dig into the details, you can educate yourself using this information from Utah State University.
If you'd rather not spend time understanding the details of relative humidity, simply understand that warm air can hold more moisture than cold air. In fact, the amount of water molecules air can hold approximately doubles for each 20-degree increase in temperature.
Moisture and Odor
Let's get to the bottom line. How much moisture is in the air is a huge factor in how well scent will disperse and how well a deer can detect odors. The less moisture there is in the air, the less likely deer are to smell you.
To illustrate this point, imagine filling a glass with water and then placing a few drops of food coloring into the glass. The food coloring moves from the top to the bottom, gets caught in swirls of disturbance and gets thinner as it moves further away from where the coloring was initially dropped at the top of the water.
Odors from hunters and their gear are also impacted by the temperature and amount of moisture in the air. Changes in temperature and moisture have a huge impact on both the strength of odors and also how quickly they dissipate. When the temperature drops, air and scent molecules become more dense.
This is why helicopters can lift more in cold air compared to hot air. Colder (denser) air also means there can be a higher concentration of odor molecules per square inch. Similarly, water vapor traps scent molecules, enhancing the odor they release and slowing their diffusion into the air. A combination of cool, moist air results in scent that is heavy and closer to the ground. This is why it's much easier for a dog to point a quail or track a rabbit during the cool morning hours versus during the heat of the day.
As another example, a few years ago I shot a deer and hit it too far back. I lost the blood trail around 10 a.m. In Missouri (where I was hunting), it's necessary to get the local conservation officer's permission to use a dog (on a leash) to trail a wounded deer. By the time I got permission and got our dog to the last place I'd found blood, the day had gotten very warm. Initially, the dog took the trail another few yards and started wandering. She was clearly having trouble finding the trail. It was obvious we were not making any progress, so we decided to give it a break and come back later that afternoon.
Once back in the woods that afternoon, we put the dog on the last sign. She immediately took off, pulling on her leash and dragging her handler through the woods. She ran straight to the deer! The dog's blood trailing skills didn't improve during the break. And the trail was hours older. But as the temperature cooled, the air got denser which allowed her to simply pick up the existing odors from the blood trail that much better!
The Freeze Factor
Cool, moist air certainly makes it easier for dogs, deer and man to detect odors. If you live in a neighborhood where folks put their trash out or there's some type of manufacturing around that gives off odor, you've probably noticed you can smell it best when it's cool and moist. However, you can be downwind of a pig or poultry farm when it's really cold and dry outside and barely smell the odor.
That's because it is also true that air can be too cold for odor molecules to be carried by air. As temperatures continue to drop, the moisture in the air freezes to a solid. Eventually, the scent becomes trapped in dry solids and cannot be detected easily by either man or beast. It is for this reason that dogs may have trouble tracking in subfreezing temperatures but do well on cool, rainy days. For the same reason, deer may not bust you due to odor on very cold or very dry days.
If you live where the temperatures and/or humidity are low during the late season, it may be a great time to hunt. You can scout and hunt more without deer detecting odors from you or your gear as easily as they can during cool, moist conditions.
The weather not only impacts when deer are active, but how well they can detect you with their sense of smell. This is simply another reason I'm an avid weather watcher during deer season. I don't simply watch wind direction; I also watch the humidity and temperature.
Hunter\'s Specialties | 180 Day Estrus
While some deer scents are formulated to work during a small window of the hunting season, Hunter's Specialties takes a different approach with 180 Day Estrus
scent. An all-natural product, 180 Day Estrus consists of premium whitetail doe urine collected during peak cycle, along with other key ingredients to ensure the scent's stability.
The scent can be used any time from September through February and is effective in a variety of applications, including for scent drags or applied to real or mock scrapes. Each bottle comes with four Spike Wicks.
Primos | Bottleneck Grunt
Better doesn't have to be bigger. With its compact, single-reed design, the new Primos Bottleneck
grunt call can produce lifelike midtone deep grunts despite its diminutive size.
The call's soft, flexible, bottleneck design helps contribute to the realistic tones while also making for a handy, pocket-sized package. The call comes with a lanyard for easy carrying and quick accessibility during the hunt.
Tink\'s | Power Scrape All-Season Scrape Kit
Hunters seeking an edge in building the perfect buck-attracting scrape setup don't need to look beyond the new Power Scrape All-Season Scrape Kit from Tink's
. The kit comes complete with all the ingredients needed to spice up a scrape site that big bucks won't be able to resist.
The foundation is Tink's legendary Power Scrape Starter, which can be used for up to a month prior to ramping up of the rut. Then it's time to switch to the all-new Power Scrape Finisher, which is specially formulated with the original Power Scrape formula enhanced with Tink's #69 Doe-in-Rut estrous and buck secretions to mimic natural scrapes closer to the rutting season. The delivery mechanism is Tink's trusted and effective Scrape Bomb Dripper.
Ozonics | HR-200
The Ozonics HR-200
already is well known for using its unique GameChanger technology to mask a hunter's scent by changing ordinary oxygen molecules into ozone molecules.
Now, the company is targeting game's eyesight as well, offering the unit in two camo patterns — Mossy Oak Treestand and Mathews Lost Camo. The units continue to employ the technology that has earned legions of converts who appreciate the odor-eliminating performance of the safe-to-use HR-200.
Evolved Harvest | 7-Card Stud
With seven different plant types, 7-Card Stud
, from Evolved Harvest, is the most adaptive food plot blend on the market, providing deer with a wide variety of protein-rich forage. Included in the 7-Card Stud mix are forage oats, forage triticale, forage turnips, winter peas, crimson clover, Daikon radish and forage chicory.
The variety ensures that the plots will be able to offer at least one deer-attracting option at all times. The seed mix is available in a 10-pound bag that covers a quarter of an acre.
Moultrie | Camera Candy
Legions of hunters have come to understand the value of using scouting cameras to monitor game on their hunting grounds. Capturing great images requires not only quality cameras but also a way to attract animals into the camera's area.
With its new Camera Candy, Moultrie
has produced a deer attractant that is specifically formulated to attract deer and keep them in the area while game cameras fire away. Camera Candy is a four-pound, hard-cooked block attractant that comes with a special strap — the CamStrap — that allows the block to be perfectly positioned to get a trophy buck's head in the center of the frame.
Montana Decoy | Miss Purr-fect
Montana Decoy is known for its line of ultra-
realistic, two-dimensional decoys created from actual photos of game in the field. The company uses that same photo realism with an additional dimension in its new Miss Purr-fect
turkey decoy, part of the company's exciting 3-D decoy line up.
Though Miss Purr-fect pops into a 3-D shape, the decoy folds almost flat for easy transport. Folded, the decoy is just 9x13 inches and weighs just 1 pound, 6 ounces. Perfect Pose technology allows hunters to finely tune the decoy's head position, and two leg-pole positions allow for setup in either feeder or looker poses.
Cabela\'s | Trophy Series Deer Mineral
Mineral supplements need to not only offer vital ingredients to promote deer health and antler growth but also need to be palatable so the animals are attracted to them.
Cabela's Trophy Series Deer Mineral
is specially designed to enhance body growth and antler development and contribute to better breeding and reproductive performance. The granular mineral, which comes in a six-pound bag, is weatherized to stand up to environmental conditions.
Heartland Wildlife | Brush Country Buffet
The often harsh climate of places such as the Texas Brush Country and other dry areas of the Deep South can create challenges when it comes to establishing lush food plots. The new Brush Country Buffet
seed mix from Heartland Wildlife is specifically formulated to thrive in areas where regular seed mixes just won't cut the mustard.
Brush Country Buffet provides a mix of nutritious clovers, ryes, turnips, brassicas and other attractants that not only grow well in tough conditions but will attract deer in droves. Each 20-pound bag will plant half an acre.
Wildgame Innovations | Scrape Blaster
from Wildgame Innovations doesn't attract big bucks with its aroma alone. The new scent is the first aerosol-powered spray that is UV enhanced so bucks can actually see it. Scrape Blaster combines pre-orbital gland scents and various deer urine scents with Wildgame Innovations' Glo-Coat technology, which makes the aerosol foam reflect ultra-violet light so deer can see it. One eight-ounce can will cover several scrapes.
Duel Game Calls | HB III Friction Series
With their innovative designs and high-grade construction, Duel's pot calls
represent some of the finest friction calls available to hunters. The calls are constructed of CNC-machined, warp-resistant laminated hardwood, producing not only a striking appearance but also laying the foundation for spectacular tones.
With a dual-chamber sounding board and one-piece pillar construction, the calls generate 40 percent better sound resonance than the average pot call. The 4-inch diameter also creates the capability of louder call volumes.
The calls are available in a Tough Country Slate version featuring ocean slate over borosilicate pure crystal, a Legacy Glass version made with the borosilicate pure crystal and a Precious Metal Aluminum with an aluminum sounding board over borosilicate pure crystal.
ScentBlocker | NoseBlocker
Scent-eliminating gear such as clothing from ScentBlocker
can help hunters avoid detection in the field by super-sniffing game. Now, ScentBlocker's new NoseBlocker scents offer another level of protection.
NoseBlocker uses a proprietary formula with a unique and powerful natural root extract to create an aroma that extensive field-testing has shown to relax wild deer. NoseBlocker is available in two versions: Drowsy Cherry Vanilla and Drowsy Apple. The scents both attract and relax deer that catch a whiff of the intoxicating aroma, so be sure to give yourself a much-needed advantage.
ICOtech Predator Calls | GC500
The new GC500
electronic call from ICOtech Predator Calls pulls together key features all hunters appreciate: flexibility, functionality and affordability.
The unit offers super simple operation, with just one button needed to activate the call. Once the call sequence plays, the unit pauses for 30 seconds before re-playing the sequence. Calls are loaded and played from a standard SD memory card, and the GC500 can play any audio file saved in the .mp3 or .wav formats (16 bit or less). The remote control has a range of up to 300 yards, with no line of sight required, helping hunters avoid detection by keen-eyed predators.
Extreme Hunting Solutions | Stick-N-Lick Deer Pop Jr.
Weighing in at just over a pound, the Stick-N-Lick Deer Pop Jr.
is a pint-sized deer attractant from Extreme Hunting Solutions. But the little bucket boasts big performance, lasting up to two months. Like the original Stick-N-Lick, which comes in a five-pound bucket, the junior version features a unique blend of hard cooked molasses, whole kernel corn and apple flavoring. The patented Weather Shield polymer packaging includes a sturdy lag bolt for mounting to any wooden surface.
Flambeau Outdoors | MAD TreeCoy
Decoys typically mimic animals, but leave it to 'œMAD scientist' Mark Drury to take decoying deer in a new direction.
new TreeCoy is an artificial tree trunk and base. Hunters simply place the decoy in a strategic spot and then clip a few limbs from nearby trees and place them into the holes on the trunk, creating a licking branch and scrape setup that bucks won't be able to resist. Easy portability allows hunters to place the TreeCoy in the best spots, and even to set up the limbs so that bucks checking out the TreeCoy will present the ideal quartering-away angle from the hunter's stand location.
Assembled, the TreeCoy is approximately nine feet tall, but it breaks down to a package that's barely three feet long.
Primos | Donkey Butter
Primos has expanded its popular Swamp Donkey line to include a concentrated deer paste attractant formulated for use in a wide range of field applications. Donkey Butter
is sticky paste that can be used at bait sites, or applied in shooting lanes to stop bucks.
It's available in Molasses or Peanut Butter flavors and comes in disposable tubes or bottles for easy application. The 3.5-ounce tube is designed for a single use, while the 24-ounce squeeze bottle contains enough Donkey Butter for approximately seven field uses.
$15.95 (24-ounce bottle)
Hunter's Specialties | Field Champion Box Call
Hunter's Specialties is harkening back to the good ol' days with its Retro Series Calls. The Field Champion Box call
is among the offerings, giving hunters who don't have an original in their arsenal the chance to take advantage of the call's realistic tone and far-reaching volume.
The Field Champion is well-suited not only for reproducing hen calls but also super-realistic gobbles. The call features a moisture-resistant green camo finish and the Silencer Plus feature to lock the lid in place for quiet transport.
Extreme Hunting Solutions | Kandy Korn with Apple Aroma
Kids at Halloween aren't the only fans of candy corn. The new Kandy Korn
with Apple Aroma from Extreme Hunting Solutions is a sweet treat that will draw in the big ones. Kandy Korn is more than an attractant. With a proprietary mix that includes oats, corn, roasted soybeans, chelated minerals and vitamins, it's a nutritious food source.
Available in six- or 40-pound bags, it can be used on its own or to supplement other feed. For example, a single bag of Kandy Korn will treat up to 300 pounds of whole or cracked corn.
$16.99 (6-pound bag)
Apparition Scents | Undertaker Scrape Starter
With its new Undertaker
scrape starter, Apparition Scents has eliminated the need for a scrape dripper by combining a liquid deer lure with
another key element of any natural scrape: real dirt. The combination of the proven Apparition Scents lure with soil makes it easy to establish a mock scrape or enhance an existing scrape to keep bucks coming back daily.
It's 100 percent waterproof, too, so will keep on working even after a deluge. In fact, the Undertaker will work up to two months,
ensuring scrapes remain attractive during the entire rut.
CarboMask | CarboMask Facepaint
Infused with activated carbon, CarboMask
face paint offers bowhunters a scent-free option for covering up game-spooking bare skin. The water-based paint uses natural clays for smooth, easy application and is not greasy. Because of the clay base, the paint is drab and doesn't create any glare. It's also easy to remove. The paint comes in color-
specific, disc-top delivery tubes (1.5 ounces) with handy paracord loops.
Moultrie | Dinner Plate Gravity Series
The new Dinner Plate Gravity Series of game feeders from Moultrie
addresses a longtime concern for hunters who use electric feeders: keeping the feed coming. Dinner Plate feeders dispense food on demand, without the need for batteries or an electronic timer.
The Dinner Plate Feeder Kit, which can be retrofitted to existing feeders, can accommodate corn or protein-type feeds up to 2.25 inches long and a quarter-inch in diameter. The 30-gallon Dinner Plate feeder is less than 6 feet tall, making for easy filling. The 55-gallon model has a 400-pound capacity.
$109.99 (30 gallon); $
199.99 (55 gallon); $
Evolved Harvest | Buck'd Up Hunter's Plot Seed Mix
New for 2015, Buck'd Up Hunter's Plot seed mix from Evolved Harvest
includes a mix of seeds that provides for year-round plots that are both attractive and nutritious to deer. The mixture includes winter grains, clover and brassicas. The highly palatable blend also contains quick-starting oats and winter wheat. The brassicas are critical because the plants' sugars concentrate in the leaves with the onset of cold weather, providing excellent forage during a time when other greens are not thriving. A 4.5-pound bag of Buck'd Up Hunters Plot will cover a quarter of an acre.
Hunter\'s Specialties | Penny Snood Feeder Hen Decoy
Lightweight and ultra-realistic, the Penny Snood Feeder Hen Decoy
from Hunter's Specialties is the kind of decoy that puts both hens and gobblers at ease as they approach a hunter's set. The inflatable decoy is constructed of durable, crease- and dent-resistant rubber and features a built-in air valve, which allows for quick deployment. The no-flake paint will remain vivid season after season and the self-balancing stake tube allows for easy placement even in the dark.
Primos | Osceola Edition
Second in line in a four-year limited edition run, the Osceola Edition is the newest addition to the Heartbreaker Grand Slam Series of box calls
from Primos. The call features single-billet box construction for crisp yelps and cuts.
Each call is individually numbered and personally signed by Will Primos, and all feature a 3-D, laser-engraved scene depicting the Osceola wild turkey. Also new from Primos is the Bamboozled Box Call, which features a super dense bamboo paddle for extremely loud, crisp yelps and cuts.
$24.95 (Bamboozled); $
69.95 (Osceola Heartbreaker)