“The nest got whacked; no sign of the hen,” my partner reported as he returned to his ATV. We recorded another nesting effort squandered as we continued our daily afternoon nest checks across the prairie in northeastern North Dakota. Both my partner Luke Gilbert and I were spending the summer working for Delta Waterfowl Foundation in the waterfowl rich Prairie Pothole Region (PPR). About half of North America’s waterfowl nest here each summer, and we are working to find ways to make that nesting effort more productive for ducks.
Luke, a third summer “veteran” with Delta, was still showing me the ropes. “Right here by the road, only a short distance from that abandoned farm stead over there, and on a control block like this, she really didn’t stand a chance. Maybe she’ll find a better spot next time.” As federal funding for grassland conservation programs like the Conservation Reserve Program (CRP) is being phased out, finding suitable nesting sites is becoming more difficult each year for the ducks. Fortunately, predator management, as it is becoming known, is making a difference.
The specific study we are working on is determining if removing the overabundant nest predators from an area will increase nest success for upland nesting waterfowl. By trapping areas of high duck nest density and thus lowering the number of the nest predators like skunks, raccoons, and red fox in those areas, Delta is ensuring that the ducks are getting the most bang for their buck on these now-valuable patches of grass. From what we were finding, it is making a big difference. Our control blocks, with no predator removal, have nest success rates far below the 12% required to maintain waterfowl populations. The management blocks, however, are seeing nest success rates averaging around 30% and sometimes much higher.
A typical day as a Delta technician starts around eight a.m. when we roll out of the driveway, four wheelers in tow. Some of the grassland fields we study are privately owned, some are in a conservation easement, and others are federally-owned Waterfowl Production Areas (WPA). The method of nest searching we use is called chain dragging. With this method, a chain, about thirty-five yards long, is connected to a four wheeler at each end. We drag this chain, at a walking pace, between the two four wheelers across the field in a pattern similar to cutting grass on a lawn. When the chain drags over a nesting hen, she flushes from her nest. The tall grass keeps the chain dragging just above the hen and her nest. As we drive, our eyes are focused primarily on the chain because when a hen does flush, we must immediately identify the species of duck, and pinpoint exactly where she jumped from. Hens that flush in front of the four wheelers make enough noise upon their eruption to avoid nest collisions. Once the nest is located, we assign the nest a number, age the eggs by candling them, mark the nest with a stake placed ten yards to the north, and record the GPS position of the nest for later geospatial analysis.
As a general rule, hens take an incubation break in the mid afternoon to feed and drink. If a hen is not on her nest, we really have no way of finding it by chain dragging so we quit nest searching for the day around two p.m. In the late afternoon, we return to some of the nests we have previously marked to check up on them. Each nest, when found is assigned a nest card that tracks the nest from the date it’s found until it is terminated. During nest checks we simply drive from nest to nest, checking them to see if all of the eggs are still there and if they are developing properly in the incubation process. A nest is terminated when it hatches, is abandoned, or is destroyed by a predator. Against popular belief, our handling of the eggs, and even newly hatched ducklings, has no effect on nest success or abandonment.
As the summer progressed, the positive effects of predator management were becoming more and more evident, even to a rooky like me. We try to drag each field every two weeks and check each found nest every five days. Fields in the control blocks would be void of active nests within one or two nest check rotations, whereas fields in the management blocks would often have nests stay active until they hatched after three weeks of incubation.
The next afternoon was a different story. I could hear the faint peeping as I cautiously approached the nest. The hen was flopping around in the grass a few yards away, feigning an injury in a last-ditch attempt to draw me away from her nest. As I pulled the grass above the nest to the side, the peeping got louder. A brood of eight Gadwall ducklings looked up at me. “They’re all hatched,” I reported back to Luke. We were conducting nest checks on a management block and this was the fourth brood we had found that afternoon out of probably thirty or forty hatched nests. The ducklings stay in the nest for about a day with the hen before she leads them to water, so only a small portion of the successful nests we checked would have ducklings in them. I snapped a quick picture with my phone, pulled the stake, and we were off to the next nest.
As a waterfowl hunter and scientist, it is of high importance to me that waterfowl populations remain strong. That means doing everything we can to ensure that the habitats waterfowl rely on are as productive as possible. Spending the summer in the PPR studying waterfowl nest success and gaining intimate, first-hand knowledge of what factors are driving duck production in this region has been incredible experience that I will benefit from both as an outdoorsman and scientist. Most all of us that are in the scientific field are here for a personal reason. We have a direct vested interest in what we are doing beyond this just being a career choice. My advice is to pursue that interest! Find something to work on that you care about. When you are working for something that you are passionate about, the travel, the long hours, and the hot days all become worth it in the end.
Maybe I’ll see one of those young Gadwalls this year on their fall migration, maybe not, but because of the work we have done, someone will. And that to me makes all the difference in the world.