Duck numbers, habitat, programs

Byline: David Bennett Farm Press Editorial Staff

With duck season nigh there are plenty of subjects to tackle with biologist Brian Davis and conservation program director, Craig Hilburn. Asked the most common question they face, the two Ducks Unlimited employees look at each and begin chuckling. Without missing a beat, together they say, "Where are the ducks?"

So, sitting in the DU North Little Rock, Ark., office, let's start there.

Where the ducks are

"Early last spring, we experienced a lot of dry conditions around the prairies," said Davis. "A pothole/breeding duck count (listed by, among other things, species and total ducks) is conducted in May by air. Another census in July counts the number of broods produced."

Because of the early dry conditions, researchers believe total duck production went from last year's 36 million breeding pairs to 32 million currently. This is part of a trend - the third year of dry prairies.

In the general mid-continent, there are between 7.1 million and 7.2 million breeding pairs of mallards. Counting the mallards in the eastern flyway, there are 8.2 million pairs (down 11 to 14 percent).

"It isn't great, but it also isn't catastrophic," insists Davis. "Birds like mallards and pintails are early breeders. Since the potholes weren't wet, the early production was hurt."

As the spring progressed, though, it grew very wet. That may set up a great breeding habitat for next spring.

Regardless, "Later-breeding birds - blue-wing teal and especially diving ducks - responded to those conditions very well. I'm told it was an odd year because there were ducklings swimming around beside birds beginning to flock up.

"Bottom line: we've had a drop in production. But with the combination of May ponds and breeding pairs, we're back in that liberal shooting package again - 60 days, six ducks a day. We're hoping to undersell and overdeliver."

The bottleneck

Hilburn, citing a common refrain over the last few years, pointed to warm weather putting the pinch on migration. "If you study flyway maps, Arkansas, Louisiana and Mississippi are at the neck of the funnel. Weather drives ducks. Some species (gadwall, pintail, and widgeons) migrate for reasons other than weather. We're seeing pintails in Arkansas now. But the majority of ducks will go just as far as they have to for food, open water and roosts. Going on four years, we've had extremely mild winters."

As if to punctuate his point, the office's air-conditioning kicks on as wasps buzz around window frames.

"It's the start of November, and we're at 80 degrees," he said. "Over the last 109 years of weather data, averaging November to February conditions, the last three are at, or near, the top. This past January, it was colder in Arkansas than in North Dakota. When that's the case - and there's vast acreage of corn with no snow cover up there, there's little reason to head south."

Typically, Arkansans see a lot of ducks in mid-December. Farther north, hunting seasons are out by early December. So the birds aren't being pressured - further lessening the need to wing it southward.

"Even with declining numbers, though, I'm the optimist," said Hilburn. "We just need a really good winter. If that happens, we'll see the ducks."

Field prep for ducks

In preliminary research in Arkansas, Louisiana and Mississippi, waste rice amounts have been studied in differently treated fields - rolled fields, burned fields, disked fields, and control fields left alone.

What was found, said Davis, is that burned fields had the most waste grain left for ducks. "The thinking is that burning the seed killed the germ. More work is needed to see if that proves out - we'll look at these treated fields for the next couple of years."

Hilburn said DU has had many graduate students looking at the amount of waste grain left in fields after harvest. "There's so little waste grain left in the fields now - because of combine quality and earliness of harvest - that birds are left with much less food. It's documented that from the harvest in September through December, there's a 72 percent decline in waste grain in the field. That shows that by the time ducks get here and we think, 'The season is getting good!' there isn't much food left for the birds."

Importance of farms

Grain isn't the only thing ducks need, though. One of the benefits of rice is that it's a grass. And grasses are often colonized quickly by insects and invertebrates - essential food sources for ducks.

"Late in the year, ducks begin going through some drastic changes," said Davis. "The plumage hens wear in the fall is known as alternate plumage (a category that a drake's green head also falls into).

"Right now, ducks are loading up on seeds and insects up north. Feathers are about 80 to 90 percent protein and much protein can be found in foods like aquatic insects and some seeds, tubers and wetland plants. In order to grow the green heads, eating many insects is required."

By the time mallards reach the Delta, most have shiny, green heads. By January, though, a mallard hen begins a pre-basic molt and essentially darkens. She does this because upon reaching nesting grounds, her color will provide better camouflage.

So, once again, the hen needs to eat aquatic insects. She also begins to store different nutrients needed to manufacture eggs.

"One neat thing about Arkansas rice fields late in winter is they host incredible numbers of tiny snails," said Davis. "They get on decoys and boots. If you pick up a handful of mud, they'll be all over. Those snails and bugs are very important for ducks' health. If farmers can maintain just a little water in their fields - even after hunting season - it helps the hens by promoting the populations of these snails and bugs. If possible, don't pull boards until mid-February."

So does burning off fields impede ducks from finding the foods they need?

"We're not sure," said Davis. "A lot of times invertebrates are in the water because they're colonizing the straw or grass. With a lot less straw and grass, that means potentially fewer insects.

"I don't know the percentage of farmers burning fields, but it doesn't seem a lot. Given the amount of rice flooded, I don't think the burning hurts."

Programs

"We work with a couple of programs, including conservation easements," said Hilburn. "By giving up certain rights to land, a landowner can get tax breaks. For instance, say businessmen from Memphis buy a tract of land and don't want to farm it anymore and want to leave it to their grandkids. They ask us: 'What to do for better duck habitat while making sure the timber stays and the integrity of the system stays intact?' We help them with those solutions."

Another program, the Arkansas Partners Project involves DU providing water-control structures and technical assistance to private landowners. Since 1994, over 149,000 acres of Arkansas land have come into the program. Some 70 percent of that has been enhancements of agricultural land.

e-mail: dbennett@primediabusiness.com