By Gary Koehler

Who has not wondered why a flock of ducks or geese flared from a blind or pit at the last minute? You know, when you were hunkered down, gun in hand, waiting for what seemed at the time to be the birds' bank into their final pass.

All of a sudden, however, just when it appeared they were headed in, they veered one way or another and departed to points unknown. What turned them off? Or what turned them on to your location? What gave you away?

Many years ago, longtime friend Paul Gillmann and I were returning from a fruitless hunting trip in the historic Illinois River Valley, where at one time the waterfowl hunting was second to none. Upon approaching the river bridge from the south at Peru, we happened to glance down at a farmer driving a tractor in the cornfield along the river bottoms below.

For whatever reason, the farmer looked up. "Geez," Gillmann said, "his face looks like a pie plate. Did you see how shiny his face was?"

Yes, I did. And that splendid, sunny, early fall afternoon registered a monumental click in our respective brain pans. If we could see that farmer's face so clearly, what would ducks think of his ultra-bright mug? We learned, and called it the pie plate lesson. And on subsequent weekend waterfowl safaris we took to "muddying up."

That entailed dipping the edge of an oar into the bottom of Lake Senachwine, and rubbing the resultant goop on our faces. That, we figured, would solve the pie plate problem. Removing the goop later in the day was yet another matter.

The point is, unlike white-tailed deer, which primarily use their noses and ears to stay out of trouble, ducks and geese utilize their eyes. It has been repeated for years that waterfowl vision is 50 to 100 times more acute than that of humans. No one, to my knowledge, has ever pinned down exactly how much better ducks and geese can see compared to humans-researchers have not put a hard-line number on the relative comparison.

Who has not wondered why a flock of ducks or geese flared from a blind or pit at the last minute? You know, when you were hunkered down, gun in hand, waiting for what seemed at the time to be the birds' bank into their final pass.

All of a sudden, however, just when it appeared they were headed in, they veered one way or another and departed to points unknown. What turned them off? Or what turned them on to your location? What gave you away?

Many years ago, longtime friend Paul Gillmann and I were returning from a fruitless hunting trip in the historic Illinois River Valley, where at one time the waterfowl hunting was second to none. Upon approaching the river bridge from the south at Peru, we happened to glance down at a farmer driving a tractor in the cornfield along the river bottoms below.

For whatever reason, the farmer looked up. "Geez," Gillmann said, "his face looks like a pie plate. Did you see how shiny his face was?"

Yes, I did. And that splendid, sunny, early fall afternoon registered a monumental click in our respective brain pans. If we could see that farmer's face so clearly, what would ducks think of his ultra-bright mug? We learned, and called it the pie plate lesson. And on subsequent weekend waterfowl safaris we took to "muddying up."

That entailed dipping the edge of an oar into the bottom of Lake Senachwine, and rubbing the resultant goop on our faces. That, we figured, would solve the pie plate problem. Removing the goop later in the day was yet another matter.

The point is, unlike white-tailed deer, which primarily use their noses and ears to stay out of trouble, ducks and geese utilize their eyes. It has been repeated for years that waterfowl vision is 50 to 100 times more acute than that of humans. No one, to my knowledge, has ever pinned down exactly how much better ducks and geese can see compared to humans-researchers have not put a hard-line number on the relative comparison.

But these birds can discern color, and they are always on the lookout for movement, which, to them, signals danger. "The first thing some people do when you tell them there are ducks working is look up," says three-time world duck calling champion (1989, 1999, 2000) Barnie Calef of Cedar Rapids, Iowa. "And that's the last thing you want them to do. Movement in the blind scares ducks."

The goal, then, is becoming invisible to the birds. And that means camouflage, or covering up. Hide yourself well, and your chances of shooting figure to increase-if you are in an area the birds are using. That, too, is integral to the formula for success. Being where the birds want to be is, in fact, more than half the battle. Being prepared once they get there is up to you. Camouflage clothing is a primary consideration.

There is a camo pattern available for seemingly every hunting locale known to man. Advantage is the official camouflage of Ducks Unlimited. Now available in original, wetlands, hardwoods, and timber patterns, the versatility may be unmatched. Selecting the appropriate pattern to fit your personal needs is dependent upon where you hunt. Marsh and timber sites may both produce ducks, but they do not necessarily share similar vegetation.

Prevailing wisdom asserts that your camouflage match the surroundings in which you are hunting. That is, if you are hunting a pond surrounded by cattails, cover your blind with cattails. And, in general, that may be true. But how then does one explain why blinds can be effective when covered in spruce boughs although there may be no spruce trees within 20 miles? One theory is that if the blind is covered early enough in the fall, the birds get used to it, and recognize the spruce hump as part of the landscape.

"We cover our blinds with spruce and oak branches," says guide Garry Mason, a native Tennesseean who has been hunting Kentucky Lake's secondary waters for more than 25 years. "What we are trying to do is make the blind look like an island. We like spruce because it holds well and doesn't break up like some things. One thing to remember is to cut the oak branches before the first frost. That way, the leaves stay on longer."

The same can be said for willow sprigs, so cut them early, too. Black willow leaves, experience tells us, remain intact longer than all others. Natural camouflage materials also may include buck brush, corn stalks, flag, tules, cane, marsh grass, reeds, scrub brush, and more.

I know this is going to sound funny, but we camouflage our blind with tumbleweeds, says Calef, who usually hunts out of a boat blind on the Nebraska portion of the Missouri River. We travelthats our forte, freelancing. Tumbleweeds are not so dark that they dont look good in a marsh situation, yet they are not so light that we cant hunt in reservoirs that are mostly gray, with some smartweed.

If you plan on hunting out of a boat, you may want to paint the watercraft in a camo pattern to help it blend in. If you typically hunt from a more permanent setting, blinds should be built long before the start of the season. Size does not matter, but by all means plan ahead. If you figure on shooting four people from the blind, build it big enough to accommodate four people and their gear, as well as dogs if they are also to be part of the package. If possible, do not have the blind facing east; looking into the sun during prime shooting time is hardly a bargain.

Small, inconspicuous blinds hidden away along the shoreline may rate among the most efficient, but there are exceptions.

Most of our blinds are 40 feet long, says Rick French, who runs Beartail Outfitters near Coldwater, Mississippi. We brush the blinds with oak and cane, and we keep brushing them with cane the whole season. The reason is, being in the guide business, weve got a lot of people leaning up against the cover and pushing it away. We are always filling in the holes. We do what we can to break the profile, because thats important. You cant hide a blind as big as ours in a field. But you can hide the hunters if they sit still. Move around, and the ducks are gone.

Frenchs blinds are indeed mammoth. Most are deployed in flooded agricultural fields and are surrounded by hundreds of decoys. These hides produce ducks on a regular basis, mostly puddlers, which, generally, are much more suspicious than diving ducks.

Big blinds dont bother the ducks. I dont know how to explain it, but I guess they get used to them, French says. I like them because they are comfortable. And theres room to move around in them without being seen.

Do what you have to do to make yourself as hard to detect as possible. But by all means, be still, and dont flash that pie plate.

Yes, ducks really can see things we can't

Can ducks really see things that we can't? Yes, they can. But this comes as no surprise to those of us who spend significant amounts of time trying to get closer to them (or getting them to come closer to us). Certainly, the entire explanation for such excellent eyesight is not completely known, but scientists have found out quite a lot.

Birds in general have relatively large eyes that make up a greater percentage of total head weight than most mammals' eyes. Size, however, is just the beginning of the difference. Inside the eye we find a complex retina.

The retina is the back portion of the eye that receives light that has passed through the lens. For most diurnal birds (those active during daylight hours), the retina is packed with adaptations for enhanced vision. Birds possess up to five times greater concentration of cone cells (color receptors) than humans.

It is logical, then, that nocturnal birds such as owls possess fewer cone cells, in favor of more rod cells (those that detect dark/light). The cone cells of diurnal birds are further associated with colored oil droplets, thus allowing greater range of color discernment. As an illustration, imagine your world colored with a 24-color box of Crayons, while a bird's is colored with a box of 64.

When you think about it, there are an infinite number of possible colors of different shades and hues. Birds simply can detect a greater percentage of those (even near-ultraviolet), owing to attributes of the cone cells. The retina of a bird's eye also has a deep concave depression- filled with cone cells-that may aid in the detection of movement of small images (including those far away).

Remaining still while in the blind or pit is key to remaining undetected. When you couple a duck's enhanced vision, its ability to learn, and natural selection working against hunters that do not put these to good use, it is not so difficult to understand why camouflage and concealment are integral parts of a waterfowler's tool kit.

-Dr. Keith McKnight, Ph.D.
Ducks Unlimited Conservation Program Specialist