By Dale Humburg
I grew up in North Iowa, and that’s where I received my early exposure to waterfowl hunting. We always looked forward to the end of October for the first major mallard flights to arrive from the north. My dad used to say, “There’ll be new birds on the 26th.” And on average, he was right.
Looking back through my hunting records, I am reminded that in 1971 and 1995, October 26 was indeed a really great duck day. But in 1972 and 1996, our hunts on that same date were busts—at least from the standpoint of ducks on the grill. Several one- or two-duck days were also included among the many hunts we had on that date from the 1960s to the 1990s. All told, we averaged just over one duck per hunter.
Dynamic patterns of weather, waterfowl habitat, populations, and hunting opportunity held true for North Iowa and still do across years and flyways. Waterfowl habitat conditions, populations, migrations, and hunter activity really are anything but average.
An Average of 4.9 Million May Ponds
When breeding ducks have returned to the prairies and parklands of the United States and Canada over the last few decades, they have found anywhere from 2 million to 8 million May ponds (the standard measure for prairie wetland abundance). Year-to-year variation in regional water conditions is a reflection of the dynamic nature of the breeding grounds. While dry conditions may not be good for that particular year’s duck crop, periodic drying is essential for the health of wetlands and the long-term status of ducks. If the water didn’t dry up periodically, shallow wetlands would soon lose nutrients, vegetation, and invertebrates important to breeding ducks and their broods.
The same wetland dynamics that are important on the breeding grounds are also in play on migration and wintering areas. Wherever wetlands are found, water-level fluctuations affect cover and food and, in turn, ducks and duck hunters. Wetland managers and hunters may be tempted to strive for stable conditions in a local setting, but this spells disaster for long-term wetland productivity. Managing for constant water levels across years, whether for guaranteed duck or hunter use, ultimately comes at a cost to both.
That’s why Ducks Unlimited looks at the big picture of waterfowl management. Complexes of wetlands on a landscape scale are necessary to ensure year-to-year duck abundance. Even then, some spots are wet and some are dry every year. And in some years, such as those in the late 1980s and early 1990s, most places are dry, duck numbers decline, and waterfowlers have to wait it out.
The bottom line from a habitat perspective is wetland habitats are dynamic. It’s the periodic drying and reflooding that “drives” them.