Colleen Walsh (left) and Madelyn McFarland scan the sky.
Mallards - Shutterstock image
On the way to the blind.
Emily Hartdegen (right) and Leslie Twiner wait patiently in a duck blind.
Trend in mallards from the coastal transect survey in coastal Louisiana.
Trend in northern pintails estimated from coastal transect survey in Louisiana.
Trend in northern shovelers estimated from coastal transect survey in Louisiana.
Trend in ring-necked ducks estimates from coastal transect survey in Louisiana.
Trend in gadwalls estimated from coastal transect survey in Louisiana
Average ducks bagged per hunter during the Louisiana duck season.

Louisiana Remains One Of The Nation’s Top Waterfowl Hunting Spots But The Sport Faces Some Significant Challenges

story by Trey Iles, LDWF Public Information


Duck hunting in Louisiana is a treasured tradition, handed down from one generation to the next. From the anticipation of the first teal hunt in September, to bagging big ducks in November, to a frosty January morning in a duck blind and the fellowship before, during and after a hunt, nothing surpasses the delight Louisiana hunters feel when harvesting waterfowl.


Even as times have changed and the digital age has altered all aspects of life, duck hunting in Louisiana remains a favored past time for some and a revered way of life for many.


But just as the digital age has forever made an indelible mark on society, several factors have conspired to change duck hunting in the Bayou State. And it hasn’t been for the better.


Ask any seasoned Louisiana duck hunter and he or she will tell you it’s not like it used to be. There seems to be fewer ducks on Louisiana’s landscape and it causes great angst for the state’s zealous hunters. Many grew up thinking that partaking in plentiful duck hunts was a birthright. There was a time when it seemed to be true. And, to be honest, Louisiana remains the envy of the nation when it comes to bagging ducks.


In the latest statistics compiled by the U.S. Fish and Wildlife Service, those hunting ducks in Louisiana bagged an average of 23.1 birds for the 2017-18 season. Only California, with a longer season and a more liberal bag limit, was better at 23.2 ducks. And in 2017-18, Louisiana was third in total ducks bagged (1.1 million), trailing only California (1.3 million) and Texas (1.2 million).


But it’s not like it used to be.


Indeed, aerial waterfowl surveys conducted by Louisiana Department of Wildlife and Fisheries’ (LDWF) biologists indicate fewer ducks might be wintering in Louisiana since the mid-1990s, especially in the coastal habitats. Since 1996, estimates from the coastal transect aerial survey show a decline from more than 4 million to less than 3 million, a period when breeding populations of ducks have been relatively high including new records in 1997,1999, 2011, 2012, 2014 and 2015 (Figures 1 and 2).


But not all duck species are showing the same trends in coastal Louisiana. Mallards and pintails, favorites among duck hunters everywhere, have declined markedly on the coastal transect survey (Figures 3 and 4). However, northern shovelers, better known as spoonies, and ring-necked ducks are increasing in the same surveyed habitats (Figures 5 and 6). Gadwalls, often the most abundant species in the bags of Louisiana’s hunters, vary widely but seem to be on a slight increasing trend (Figure 7).


When looking at the mid-winter survey of the entire state, instead of just the coastal zone, the data are a lot more variable but an important recent trend seems clear. The five-year averages in total ducks since 1996 show Louisiana is wintering a smaller proportion of the ducks in the Mississippi Flyway (Figure 8).


Fewer ducks wintering in the state is certainly not good for hunting success but the relationship between these trends and our hunting success is not as clear as you might expect. The average number of ducks bagged per hunter during the duck season has declined from nearly 30 in the 2010-11 through 2013-14 seasons to less than 20 in the 2015-16 through 2017-18 seasons (Figure 9). That decline in duck hunting success is disappointing but it is similar to that in the early-2000s.


However, it gets downright maddening and disconcerting that the recent decline in hunting success came while the duck breeding population was far higher than in the early-2000s (Figure 2).


Why? Unfortunately, there is no one answer and no easy fix, especially when not all species are showing the same population trends. Migration and wintering distributions of waterfowl change continuously in both short and long term, one of the real advantages of having wings.


Many ingredients interact to change the landscape used by waterfowl; coastal wetland loss, wetland habitat degradation, less waterfowl-friendly agricultural production in Louisiana and more in states to the north, increasing temperatures, invasive plant species. All have likely contributed to the changes in migration patterns and winter distribution of ducks into and across Louisiana.


It’s like what makes a great gumbo: Not just one ingredient.


If the interactions of all those factors aren’t confusing enough, year-to-year variation in weather, habitat quality, reproductive success on the breeding grounds and other factors mask or amplify the effects of the long-term changes.


“We have so many things working against us,’’ said LDWF Waterfowl Program Manager Larry Reynolds, who has worked in this capacity for 11 years. “We all wish we could find the root cause and address it. I love being a part of the duck hunting culture in Louisiana. I think we have to recognize the challenges facing us and work to improve the things we can. We didn’t just wake up one morning and there were fewer ducks. This has been gradual. So fixing it won’t be simple either.’’


Everyone has an opinion on what the problem is. To gain the fullest understanding it’s best to look to the science.


Disappearing Coast and Climate Change

Though you can hunt waterfowl in almost every nook and cranny in the state, no region of Louisiana better exemplifies what has become of waterfowl than along the state’s fragile coastline.


“The most recent analysis from the U.S. Geological Survey shows 2,006 square miles in coastal parishes has been converted to open water since 1932,’’ Reynolds said. “With the loss of that wetland habitat, we have seen a reduction in the capacity of our coastal wetland ecosystem to support ducks. Using the energy necessary to support a duck during the wintering period, scientists estimate Louisiana’s coast can support nearly 3 million fewer ducks than in the past.’’


LDWF’s Coastal Resource Scientist Manager Todd Baker, who is overseeing the department’s coastal restoration efforts in the state’s restoration master plan, and himself an avid duck hunter, said the loss of Louisiana’s coastal land costs duck hunters all over the state.


“Coastal wetlands are the most important early-season habitat for migrating waterfowl and where they tend to arrive first because they are more stable habitats,’’ Baker said. “So all hunters north of the coastal zone benefit from maintaining a strong migration to the Louisiana coast. If you lost those wetlands and submerged aquatic vegetation on which game and non-game birds rely, what’s the attraction for them to come here? Our coastal resources have dwindled, and the shrinking overwintering waterfowl numbers are reflecting that loss of ‘stable habitat.’’’


Resources mean more than just coastal wetland area. In addition to conversion to open water, much of the remaining marsh has been degraded by saltwater intrusion or hydrologic alterations that reduce food production necessary to support a robust winter population of ducks.


Climate is a fundamental evolutionary factor influencing migration. Ducks migrate south to escape the cold, snow and ice that make it difficult to find food necessary to survive.


But every wing beat south in the winter is one to be made on the spring return to the breeding grounds. And flight is the most energetically expensive activity for ducks. So there are clear benefits to not flying any further south than necessary.


Studies of banded mallards show the distribution of recoveries shifts to the south in colder winters and to the north in warmer winters. So long-term increases in temperature would likely produce a more northern distribution of wintering ducks.


Minimum average temperatures in states north of Louisiana have increased significantly over the last 50 years. In North Dakota, for instance, the minimum average temperature has increased about 6 degrees in the last 50 years. Additionally, the number of winter days below zero have been well below the average since 1980.


Researchers in Mississippi and Missouri developed a Weather Severity Index (WSI) that incorporated temperature, snow depth and duration of below-freezing temperatures and measurable snow. They showed a relationship between WSI and migration of mallards in Missouri that explained about 40 percent of the variation in their change in abundance.


Colleagues expanded use of WSI to 25 locations in the Atlantic and Mississippi flyways and other dabbling duck species, and all showed similar relationships. Most importantly, because of increasing temperature and decreasing snowfall, WSI showed a significant decline from 1979 to 2013, enough to allow millions of dabbling ducks to winter further north. Unfortunately for southern duck hunters, current climate models predict that will continue.


Changes in Agriculture Production

Drive in the coastal prairie of southwest Louisiana and you’re bound to notice the numerous flooded fields used in rice production, which can also double as crawfish ponds. Growing rice in Louisiana has been an important part of the Bayou State’s agriculture economy for generations.


But through the last 40 years, acreage used to produce rice in Louisiana has dropped drastically. That’s bad news for wintering waterfowl. Since the middle of the 1970s, rice acreage has fallen by an incredible 40 percent.


Rice farmers also cultivate new varieties that tolerate herbicide treatments to virtually eliminate annual weeds and other plants that in the past provided foods for ducks. With vastly improved harvest efficiency, far less waste grain is left in the field and less overall food is available for migrating and wintering.


“A harvested rice field in the 1980s provided more than 400 pounds per acre of waste grain and additional seeds from other annual weeds,’’ Reynolds said. “Now that number is only 75 pounds per acre of waste grain and there is virtually nothing else.”


Waterfowl managers have calculated a give-up density of 50 pounds per acre. That is the point where ducks abandon a field because it costs more energetically to continue foraging than to find another field with a higher density of food.


“So when we consider the give-up density, the amount of available food for wintering waterfowl in a harvested rice field has declined about 90 percent since the 1980s,’’ Reynolds said. “So we have fewer acres of rice and the acres we have provide less food for ducks. In addition, crawfish farming has expanded greatly in Louisiana and a large portion of those farms utilize harvested rice fields. Typically, deeper flooding, more disturbance and active hazing of birds on crawfish farms make those fields less available to waterfowl.’’


While Louisiana has lost rice-growing acreage, it has increased to the north in the Mississippi Flyway, the waterfowl migration route that follows the Mississippi, Missouri and lower Ohio rivers in the United States across the Great Lakes to the Mackenzie River and Hudson Bay in Canada.


As an example, there is now 30 times the amount of flooded rice habitat for duck hunting in Missouri as there was 20 years ago.


Beyond rice, there have been huge increases in the corn production in northern Mississippi Flyway states. Since 1990, combined corn acreage in North Dakota, Minnesota, South Dakota, Nebraska, Iowa and Kansas has increased by almost 12.6 million acres.


Corn is an important food for migratory and wintering waterfowl, especially geese and mallards. Some other species will use flooded corn habitats to varying extents and some generally won’t.


It’s important to recognize that the species not coming to Louisiana like they used to, like mallards and pintails, tend to be those well adapted to agriculture habitats. Expanding agricultural habitats further north complement the effect of climate change in enhancing habitat available to migrating and wintering birds in those areas.


Invasive Aquatics are Bad for Business

Not all plants are welcome in Louisiana’s wetland systems. Some species, like water hyacinth and giant salvinia, have choked many waterways throughout the state and covered thousands of acres of marshes, ponds and lakes that were previously productive habitat for wintering ducks.


They form impenetrable mats on the surface, blocking all light transmissions so duck food plants like pondweeds, southern naiad or coontail can’t grow and habitat quality for wintering waterfowl drops to zero.


LDWF allocates substantial resources combating those invasive species but the battle is difficult and expensive. Reynolds points to the Maurepas Swamp in southeast Louisiana to show how invasive species have played a part in the problem.


“A very popular commercial duck hunting video, The Duckmen of Louisiana featuring Phil Robertson and Warren Coco, was filmed in the late- 1980s in the Maurepas Swamp,’’ Reynolds said. “Mallards, gadwall, wigeon and wood ducks frequented that area in good numbers. But today, that same area is a solid mat of salvinia with a community of sedges growing on it. There haven’t been good numbers of ducks in that swamp, except for an occasional wood duck, in years. It went from being a productive duck habitat to virtually nothing at all. Very little duck food production out there.’’


Expanses of marsh in southwest Louisiana and reservoirs in north Louisiana have seen similar infestations, reducing the capacity of those habitats to support wintering waterfowl. Consequently, private leaseholders and public lake hunters alike have lost hunting opportunity and struggle to take back their duck holes.


Looking Ahead

Though the picture isn’t as nice as it used to be, LDWF and other partners are working to maintain, and in some areas improve, the great tradition of waterfowl hunting in Louisiana.


Several telemetry projects by LDWF are helping biologists gain a better understanding of waterfowl migration patterns, and the factors that influence them, to inform management decisions. LDWF is also constantly working to improve habitat throughout the state, on Wildlife Management Areas, private lands and certainly in coastal Louisiana.


Louisiana is the midst of ambitious coastal land restoration project. Of the approximately $5 billion in National Resource Damage Assessment, or NRDA, funds from the BP Oil Spill, $4 billion is designated for coastal and nearshore habitat. That’s prime waterfowl country.


“This will not only benefit the coastal birds whose populations were decimated by the BP Oil Spill, it will also benefit waterfowl,’’ Baker said. “Every acre of wetland that we have right now is getting closer to the coast. Those marshes that used to not be considered on the frontline are on the frontline now. The more we can put those projects to the south, the more buffer we create along with excellent habitat for waterfowl and non-game coastal birds.’’


LDWF is working to recruit new hunters, be they waterfowl or other game, through several initiatives as well as educate hunters.


“We have a strong hunting and outdoor culture in Louisiana,’’ said Eric Shanks, who oversees the LDWF Hunter’s Education program. “That’s never going to go away.’’


Even with smaller average winter populations and lower hunter success recently, Louisiana’s waterfowl hunting experience remains an integral component.


And that culture, along with the passion shown by the state’s waterfowl hunters, will help keep the sport strong as it adapts to the new normal and changing landscape.


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