Summary:To fully understand why concealment is so important to your waterfowl hunting success, here is a birds eye view of what ducks and geese see when you're out in the field.
The following excerpts are taken from the 1996 September/October Ducks Unlimited Magazine article entitled, "What the Duck Saw" and from the 2001 March/April Ducks Unlimited Magazine article entitled, The Great Cover-Up" and "Yes, Ducks Really Can See Things We Can't".
"It is impossible, with our binocular vision and narrow visual field, to imagine how the world appears to a duck"... - H. Albert Hochbaum
"Unless of course, you can imagine your eyes the size of grapefruits and stuck about where your ears presently reside. This would be a start, but it wouldn't be enough. Even with platter-sized eyes to port and starboard, we humans still couldn't visually experience our surroundings as acutely as can ducks, which, like other birds, have the keenest vision of all vertebrates. Compared to a duck's visual abilities, in fact, we human vertebrates have tunnel vision and a nearsighted, blurred view of the world.
Birds' eyes are similar in construction to ours. They have excellent color vision, and their optic nerves, which carry visual messages to the brain, are similar to our sight-sensory pathways. What a duck or a human "sees", after all, is really a series of continuous images formed in the brain from light exciting photosensitive nerve cells in the eyes. But despite the overall similarities in ducks' and humans' optical equipment, there are also dissimilarities and the images that form in a duck's brain when it views the same scene a human does is something we cannot deduce.
Still, by studying the optical equipment ducks carry, we can make some comparisons and describe how humans might see the world through a ducks' eyes.
Unlike the human eye, which is oval-shaped, like an olive, a duck's eye is flattened, its cross-sectional share lenticular. So, structured, the duck's eye serves like a super wide-angle lens on a camera, capturing a wide field of vision. This eye shape, along with its large size, allows the duck in one glance to see close and distant objects in sharp focus (great depth of field, in photographers' terminology) over a large part of the horizon. Thus, with one eye pointed outward on each side of its head, a duck can survey an extremely wide field of view. The common pigeon, which has similarly shaped and positioned eyes, enjoys a total visual field of about 340 degrees. This means that a duck or pigeon, except for a narrow wedge of blind spot immediately behind its body, can sharply view objects near and far in almost a full circle around and above itself without having to turn its head.
So what advantage does a duck receive from having large, wide-set eyes and largely monocular, instead of largely binocular vision? First, when flying at high altitudes, ducks need little depth perception. When on the ground or paddling on the water, where they are most susceptible to predators, their wide-set eyes and sharp monocular vision allow ducks to better detect predators above and around them.
In other words, a duck's optical equipment and visual abilities are adaptations best suited to serve the bird's lifestyle. And when a fellow duck hunter asks you why ducks have such large eyes, now you can reply, "the better to see you with."
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 on way or another and departed to points unknown. What turned them off? Or what turned them on to your location? What gave you away?
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."
Taken From - "Yes, Ducks Really Can See Things We Can't"
"Can ducks really see things 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 the 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 cone 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 the 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, its not so difficult to understand why camouflage and concealment are integral parts of a waterfowler's tool kit."
Based upon the information provided above, it's very easy to see why concealment is such a vital factor to your overall waterfowl hunting success.
In addition, the information blows away a commonly held myth that ducks and geese are colorblind and only see in shades of black and white. As you can see, nothing could be farther from the truth. Also, their keen eyesight and their ability to learn and adapt only gives additional proof to the fact that both ducks and geese can detect and will often avoid objects (i.e. blinds) that do not fit in to and match the natural surroundings.