Mystifying Mottleds

A group of scientists is studying our resident duck — a bird that teases and tantalizes but seldom seals the deal.

There aren’t many Louisiana duck hunters who haven’t been snubbed by these guys. No matter how well you hide in your blind, no matter how sweet your calling may sound or how realistic your decoy spread might be, somehow they just know.

It’s not too bad when there’s other, much less educated, species to keep your guns busy, but when the hunting’s slow, they’re always there taunting, ridiculing and downright embarrassing even the most astute waterfowl hunters.

It’s rare to find one in a hunter’s bag for they are the PhDs, the magna cum laude of all ducks — the dreaded mottled duck!

Mottled ducks, close cousins of mallards and black ducks, are Louisiana’s only resident species. This means by the time all the migrating birds arrive, they’ve already been here since birth. And when all the other ducks head north in the spring, they stay put. Maybe it’s the crawfish, the jazz or the Cajun zydeco music, who knows? For whatever reason, this single species has decided to make coastal Louisiana its permanent home.

And because of that, their populations cannot be easily estimated and ultimately managed like all other waterfowl species. The nesting and breeding success of other species is heavily scrutinized in the more researcher-friendly habitat of the prairie potholes and other northern terrain.

So just how do Louisiana Department of Wildlife & Fisheries waterfowl biologists trap, band and study these dark little critters that rarely venture out from the thick, soggy protection of their marshy environment?

Over the summer, I had the chance to find out firsthand exactly how mottled ducks are studied. Led by biologist Jeb Linscombe, a team of four airboats headed into the pitch darkness of bug-infested Rockefeller Wildlife Refuge in Cameron Parish in search of ducklings and molting adults at a time of year when both are pretty much “flightless.”

It was easy to see this was not this crew’s first duck rodeo. Skillful drivers twisted and turned the raucous boats toward ducks frozen stiff from the airboat engine noise and temporarily blinded by the Q-beam lights and headlamps worn by the “catchers.”

The catchers used their hands like froggers, and gently stuffed each bird into a PVC pipe tunnel that led to a decoy sack. In the couple of hours I spent on the airboat, the total catch was around 200. By the time the night would end, it would be closer to 500.

If I learned anything that August night about mottled ducks, I discovered it’s a heck of a lot easier to catch them with an airboat than to lure them into shotgun range!

When the bags get full, the boats head to a prearranged meeting site, where each bird is sexed, aged and recorded along with an identification number on a U.S. Fish & Wildlife band that is attached to its left leg.

Up north, cannon nets, baiting and other techniques are used to capture and study ducks, but here in Louisiana those methods and typical nest counting just don’t work. That’s where Cajun ingenuity comes in.

“This is the best way we’ve found to catch them,” Linscombe said. “It’s the only thing that works in the places we find them. I can tell you where they’ll be by looking at the habitat. The places we’ll find them are some of the nastiest places in the marsh with mud flats, very shallow water and the thickest vegetative cover around.”

So with an effective way to catch and study mottled ducks what have we learned about them? Very little — not that a lot was expected.

But what we have discovered is extremely important to hunters.

“In order to justify our three-bird daily bag limit as opposed to Texas’ one, we have to show that the number of ducks here in Louisiana is stable from year to year — that loss of habitat, natural mortality and hunting are not harming the survival of the species,” Linscombe said. “The data reflects that the population is very stable. We can’t give exact numbers, but we know the population has remained flat for many years, and that’s what’s important.”

Here’s what the 12-year program has revealed:

1) Survival rate is around 50 percent each year, lower than other species but consistent.

2) The Louisiana and Texas mottled duck population is one and the same.

3) Hunter-caused mortality is very low compared to total mortality. (Anyone who has ever tried to hunt mottled ducks already knew that.)

Thanks to Linscombe and his staff, we now know a lot more about the life cycle and biology of mottled ducks.

But what about their instincts and natural tendencies that make them the wariest duck that ever flew across Delacroix and Delcambre? And just how do you go about getting into the psyche of a duck (if waterfowl even have a psyche)?

I decided to take a tip form all those investigative-type TV shows. You know the ones that use profilers to track down serial killers. After all, who better understands the quarry than those who relentlessly (and many times hopelessly) pursue it? That’s right. I went straight to those who encounter them the most. I sought the advice of professional duck hunting guides.

First, the profile: The adult mottled duck is about 21 1/2 inches long. It has a dark body, lighter head and neck, orange legs and dark eyes. Both sexes have a shiny green-blue wing patch, which is not bordered with white as with the mallard. Male and female are similar, but the male’s bill is bright yellow, whereas the female’s has a greenish-yellow hue. The plumage is darker than female mallards, especially at the tail, and the bill is yellower. In flight, the lack of white border to the speculum is a key difference.

The black duck is darker than the mottled duck, and has a bluer wing patch. The behavior and voice are the same as the mallard.

Five-time state duck calling champion Mike Smith, who operates a duck-hunting guide service in Reggio, has had many mottled duck encounters over the last couple of decades.

“We generally don’t target mottled ducks, but in 2004 we had more than I had seen in the 15 or so years before then,” he said. “They are definitely one of the toughest ducks to bring into range.

“I’ve found that hunting a blind with a roof cover helps a lot, and early in the season they’ll respond to a motion decoy.

“If I were to target them, I’d hunt in a broken marsh — maybe not in a blind at all but in some tall grass, use just a few decoys and call very little if at all. Mottles are so wary that sometimes they’ll turn away as soon as they hear the first note.”

That advice is from an expert caller.

Ryan Lambert, operator of Cajun Outdoor Adventures in Buras, agrees with Smith.

“It’s pretty simple,” he said. “You might shoot them pretty easily opening day and the first week of the season, but after that, it’s over. You’ll have to hunt them in small potholes, use a half dozen decoys and use a mallard call. Just be careful not to overcall.”

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