"I remember another blind in a cypress swamp," Checkett continues. "It was covered with slabs of [sawmill-cut] cypress with the bark showing on the outside. It was built with a cypress tree on the back corner with limbs spreading out over the back of the blind. It was very realistic."
Blinds in open agricultural fields are especially challenging to hide. Many hunters have switched from stake blinds or floating blinds to pits, but Harris says it's amazing how well pits show up from the air, especially those in wide-open harvested areas. "Hunters should try to locate their pit in a levee or next to a gully or some other linear feature in the field," he says. "Also, if the pit is in the middle of a crop, like standing corn, plant the corn all around the pit, and be careful not to knock your cover down."
Roetker says that, from the air, blinds stand out when they are higher than surrounding vegetation. "The blind should not be taller than the natural cover," he says. "If you're building a blind in cattails, brush or a standing crop, keep the profile low so it won't draw attention."
Checkett offers two more tips for camouflaging a blind. "From the air, a box-shaped duck blind looks like a box-shaped duck blind. Hunters need to soften the hard edges and round out the shape.
"Also, many hunters brush the sides of their blind really well, but they neglect the top," Checkett says. "Remember, this is what the ducks are looking at the most. Camouflage the top as well as or better than the sides, and close up those shooting holes so the ducks can't see down in them."
All three biologists warn against looking up when ducks are overhead. "From the air, human skin shines like a mirror," Harris says. "It's unbelievable how well you can see it. I'll be flying toward a blind, and when a hunter inside looks up at me, his face is the first thing I'll notice."
Harris recommends several remedies for this problem. "When the sun is bright, use a camo mask or camo face paint," he says. "Wearing gloves is also a good idea, and be aware that any metal object can reflect light—a watch, other jewelry or a shiny gun barrel. You have to keep these things out of bright sunlight."
Checkett says movement in a duck blind is very noticeable from the air. "Even if the shooting hole is well brushed, if there's somebody moving around down in the blind or pit when I'm directly overhead, I can see them," he says, "and I'm sure the ducks can too.
"As the season progresses, blinds lose camouflage," Checkett adds. "Natural vegetation gets knocked down, and blinds become more and more obvious. So it becomes critical to add new cover to the blind or maybe even to quit hunting it. Maybe it's better to go lie on the levee or bank and cover up with a grass mat. This might be what it takes to stay one step ahead of the ducks."