Years ago, when I was in the Air Force, I had a crackerjack hunting spot in north Texas that was a veritable garden of aquatic vegetation in shin-deep water, and the gadwalls loved it. Like many duck hunters, my friends and I called them "gray ducks" because of their mottled gray appearance, and they afforded us some great hunting during the years I lived in the Lone Star State.

Today, the gadwall population is flourishing. The 2009 spring waterfowl survey estimated these birds at more than 3 million—a whopping 73 percent higher than the long-term average. As a result, gadwalls provide excellent hunting opportunities in many parts of the country.

To hunters, these ducks can be both a blessing and a curse. Some days gadwalls bomb the decoys and provide fast shooting. Other days they circle maddeningly, looking as if they're going to come in on each pass and then juking for altitude at the last second. Indeed, they are finicky and often frustrating to hunters. So how can hunters increase their success on these popular birds?

To learn more about hunting gadwalls, I asked three experts: Lamar Boyd, who with his father runs Beaver Dam Hunting Service on Beaver Dam Lake in Tunica, Mississippi; Jeremy Seals, a guide on Reelfoot Lake in Tennessee; and Brett Lofton from Lafayette, Louisiana, who hunts every day of the season in the coastal marsh near Pecan Island. All three of these locations are well known for attracting large numbers of gadwalls.

"Gadwalls are our main ducks on Beaver Dam Lake," Lamar Boyd says. "We use a lot of gadwall decoys, and we call gadwalls like we call mallards. But each day we gauge how much to call by the response of the birds. The first couple of groups in the morning tell the tale. Many days they're spooky; they'll circle and circle. On these days we cut the calling way back and use a lot of contentment calls and not much hail calling.