It’s opening day in the Atlantic Flyway and you already have your wood duck limit. Now it’s time to wait for a flock of greenheads to fly by. Finally, the mid-morning flight picks up, and a group of mallards finish perfectly into the decoys. You drop two drakes out of the flock. Naturally, you’re ecstatic because killing mallards in the East is no easy task. But what if I told you that those greenheads aren’t actually wild mallards?
A recent DNA study out of the University of El Paso found that less than 5 percent of mallards sampled from the Atlantic Flyway were fully wild. The rest showed farm-raised genes—genes that change the way mallards behave. These genetics could also have a huge impact on Atlantic Flyway hunter success for years to come.
The idea that farm-raised mallards are hurting greenhead numbers is nothing new, but recent data suggests these genes are altering migration patterns, feeding habits, and nesting productivity. While there is still much research to be done, the initial results show that farm-raised mallard genes are bad for the wild population. And it leaves some hunters wondering why mallard releases are still allowed today.
The History of Farm Mallards in America
If you do most of your duck hunting on public land or on private land with free permission, you may not know that hundreds of thousands of farm-raised mallards are shot every year by fellow hunters. Game preserves and hunting clubs up and down the East Coast routinely release captive mallards so clients and members get more shooting and put more birds in the bag. This has been going on for decades.
So, what’s the big deal if hunters release and shoot ducks on private land? After all, one of the leading reasons farm-raised mallards are still released today is because hunters and experts alike have always assumed that these birds have no impact on the wild population. But these farm birds are not your typical greenheads. They may look like normal mallards, but most are of European origin and feature a genetic makeup different from that of a North American wild mallard.
“Mallards started being released in the 1940s, but the floodgates didn’t open until the mid-’80s,” says Dr. Frank Rohwer, president and chief scientist of Delta Waterfowl. According to Rohwer, in 1986, the USFWS loosened the release-and-harvest regulations on captive-reared mallards, which allowed landowners to shoot as many farm-raised mallards as they wanted as long as their land was licensed as a regulated shooting area.
Rohwer references hunters in his home state of Maryland who did just that—in spades. “Some landowners with RSA status released over 100,000 mallards [in the span of a few years] near Cambridge, Maryland,” says Rohwer. “Many others released 20,000 mallards and the total number of released captive-reared Mallards [in the state] was likely to be more than a million birds throughout the late 1980s and early 1990s.” And that’s only one state. Many other hunting clubs in the east also released mallards, contributing to a large influx of farm birds into the Atlantic Flyway.
In the 90s, Rohwer worked as an academic researcher at the University of Maryland, where he got funding from the USFWS, Grand National Hunt Club, and the Maryland Department of Natural Resources to study captive-reared mallards. “We developed a project to see the effect of released mallards,” says Rohwer. “And frankly, we didn't see much.” The methodology at the time involved marking farm mallards with bands to see if they paired with wild (unbanded) mallards. They found little mixing. However, that study did not include DNA testing. “Nobody was talking about genetics back then,” says Rohwer.
That’s what has changed. Now, over 30 years later, researchers and biologists are looking at the genetic makeup of Atlantic Flyway mallards—and they are seeing these genes in the wild population.
DNA Analysis Shows Farm Genetics in Wild Mallard Population
In a paper published in 2023, Associate Professor Dr. Philip Lavretsky at the University of Texas at El Paso, conducted a genetic sampling—a combination of live and harvested birds—of almost 1,000 mallards in the Atlantic Flyway. He found that only 2 percent of those mallards were genetically wild. Think about that for a second: If over the course of a season, or two seasons, you and your buddies shot 100 mallards (in the Atlantic Flyway), only 2 of them would be fully wild. Some states, including Rhode Island, Connecticut, and New Jersey, produced almost no wild birds in the study whatsoever.
You may be thinking, why does it matter if my duck has some farm-raised genes when they are both mallards? Well, because genetically speaking, it’s a stretch to call the farm-raised ducks “mallards” at all. “Genetically, farm-raised mallards are about 10 percent different than a wild mallard,” says Lavretsky. “To put that in perspective, a black duck and a wild mallard are only 1.5 percent genetically different. In the bird world, that [10 percent difference] would be a full species.”
And it's not just the genetics of these birds that differ. Farm-raised mallards have shorter, wider bills, shorter wings, and longer legs. “These birds have been transformed to be more chicken-like than duck-like,” says Lavretsky. Most important, researchers have found that once a mallard’s genetic makeup exceeds 30 percent farm-genes, the bird starts to exhibit maladaptive traits that could even be responsible in part for the decline in mallard populations.
How Farm-Raised DNA May Be Hurting Ducks and Duck Hunting
Shooting mallards that don’t look quite right is one thing, but birds with genes that change feeding habits, nesting success, and behavioral traits have more serious consequences. Associate Professor at SUNY-ESF, Dr. Michael Schummer, is also studying the differences between game-farm and wild mallards. Schummer and his team put birds in experimental cages with different-size seeds and gave them the opportunity to feed. The results showed game-farm birds are taking in food at about 50 percent of the rate that wild birds are.
“Not only are the bills physically different, but they seem to ingest food or have some effect on ingesting food at a lower rate,” says Schummer. “Fat is good for surviving; it's good for producing eggs. And when you're feeding at half the rate that your wild counterpart is, that’s a bad thing.” Basically, it takes mallards with farm genetics twice as long to get the nutrients to produce eggs and migrate. And if these birds fail at nesting, it will take them twice as long to get those resources back to re-nest.
“When we were raising game-farm mallards in captivity for this study, they would just walk along and drop an egg in the middle of summer,” says Schummer. “They're not on the cycle that normal mallards are.” In comparison, wild mallards typically lay eggs in the spring for about 10 to 12 days, before sitting on and incubating the nest for about 28 days.
Schummer’s studies also showed that game-farm mallard hens seemingly have no instinct to sit on their eggs. And hens that don’t attend to their nest sufficiently decrease the chances of egg survival. When talking to Lavretsky, who works closely with Schummer, he explained that for every wild hen, it takes 3.3 game-farm or hybrid hens to produce the same number of ducklings. So, as the population becomes more and more farm-like, bird production decreases by 66 percent.
How Farm Genetics Impact Migration
Over the last couple of duck seasons, hunters across the entire country have complained about the lack of migration. Some of the newest data suggests that game-farm genetics may be contributing to the problem in the Atlantic Flyway.
Lavretsky teamed up with other researchers conducting telemetry projects to take genetic samples and monitor bird migration. His team found that if a bird is under the 70 percent wild genetic mark, they start to show signs of what Lavretsky calls “a random walk in migration.” The results are eye-opening.
According to Lavretsky, birds under this wild-gene threshold have two or three times more stopovers during their migration, and the duration of those stopovers are longer than fully wild mallards. As Lavretsky explains, this shows that mallards with more than 30 percent farm-raised genetics “aren’t queuing to migrate” or in other terms, aren’t preparing for long flights. And when they do migrate, they don’t know where they are going.
Referencing Schummer’s studies on feeding habits, Lavretsky says, "We now have data that shows farm ducks have trouble putting on fat. These birds are essentially jets without fuel.”
Lavretsky points out that additional studies, which they are hoping to publish in the coming months, are finding the exact same trend. “The more game farm [genetics] you have, the more you show a random walk rather than a migratory path.”
So, what does this all mean for hunters? Based on initial findings, it could well mean fewer birds migrating south and fewer mallards on duck straps. And the last thing waterfowl hunters need is another contributing factor to already poor migrations.
How the Latest Data Is Being Received by Conservation Organizations
While there has been more attention and research around the impact of farm-raised mallards in recent years, some biologists still aren’t convinced mallard releases are to blame for a declining population. “Releases of captive birds have been going on for many decades, says Rowher. “So, I am skeptical that this has had a measurable impact on survival or reproduction of wild stock mallards. So far, I have seen no evidence of such effects. It is possible, but not likely. That is [my] opinion until some informative data comes along.”
Habitat loss and degradation still remain top issues facing mallards and other waterfowl species across the continent. “The decline of eastern mallards appears to be limited to the U.S. side of the border and seems more likely to be a habitat/predation issue than a genetic issue,” says Rowher.
Ducks Unlimited is also tracking the potential issues surrounding game farm mallards. “Hybridization with game-farm mallards is of increasing concern to Ducks Unlimited, as new evidence suggests these hybrids are less productive and may not migrate the same as wild mallards,” says DU Senior Waterfowl Scientist Dr. Mike Brasher. “Fundamentally, we believe our success in waterfowl conservation should be measured by our ability to sustain populations of genetically wild waterfowl.”
The duckDNA Project
With all these new study results, researchers are now looking for potential solutions and better ways to educate hunters. Last year, Ducks Unlimited partnered with Phil Lavretsky to launch duckDNA as a way to engage hunters in DNA research. “The idea originated out of an interest in providing hunters with some sort of ancestry on hybrid birds,” says Brasher. “We quickly realized that there's an opportunity to do much more than that, to contribute to various scientific questions around waterfowl genetics.”
One of the big questions surrounding waterfowl genetics, of course, is the impact of game-farm mallards. The duckDNA program allows hunters to send in a tissue sample (a piece of the tongue) and DU will then provide a genetic breakdown of the bird. Think of it as ancestry.com for ducks. “In exchange for submitting a bird, hunters receive a certificate of pedigree that tells them the genetic percentage makeup of the samples that they've selected,” says Brasher. “These results can determine whether the bird is a hundred percent wild mallard, a hundred percent wild black duck, or if it has some hybrid ancestry [including farm genetics].”
Ducks Unlimited emphasizes its interest in this project goes beyond just providing data for the study of game-farm genetics. That said, this program will undoubtedly help researchers gain a better understanding of farm genetics on the landscape. Last year DU enrolled 300 hunters with well over 4,000 applicants.
The study is nationwide, and duckDNA is focused on samples from the mallard family—black ducks, mallards, mottled ducks, and Mexican ducks, as well as any species of duck with a unique physical appearance. Ducks Unlimited also gives hunters who weren’t selected the opportunity to contact them if they shoot a unique hybrid. This year, they are looking to enroll 600 hunters in the duckDNA program.
Earlier this year, on New York’s opening day, I shot a mallard with unique coloring. Based on the appearance, I decided to submit a DNA sample to the duckDNA program. The results, along with an explanation of the sampling process, will be featured in a follow-up story.
The Future of the Atlantic Flyway Mallard
More research must be done to better understand the impact of farm-raised mallards on wild populations. However, initial DNA results and telemetry studies clearly suggest that farm-raised mallard releases are bad for ducks and duck hunting—and that should be a concern, at minimum, for every waterfowler.
“We're doing robust studies with large sample sizes, and it's really saying that game-farm mallards are on the landscape and game-farm genes are not good for the wild mallard population in North America,” says Schummer. So, what can be done to fix the problem?
According to Lavretsky, it would require some serious management work, but restoring a wild population of greenheads is possible. “We built models, and it suggests that we could transform the Atlantic Flyway back to better than 90 percent wild in three generations, which is respectively three years,” he says. “If we could pump about 60,000 wild mallards back into the system (assuming game-farm mallards are no longer being released), we could help restore the wild genes.”
As eastern mallard populations continue to decline—down 4 percent from 2023 and 9 percent from the long-term average—Atlantic Flyway hunters' straps stand to see fewer and fewer greenheads. And if ongoing studies continue to show farm genetics impede wild instincts and natural migration patterns, the USFWS and Atlantic Flyway Council may have to prohibit private land mallard releases. Many hunters might also want to see those regulations changed if it means more wild greenheads in the air.
At the end of my conversation with Mike Schummer, we discussed the role of hunters in this farm mallard problem, and he posed a great question, “How gross would it be for hunters to be responsible for the demise of Atlantic Flyway mallards?"
