Waterfowl Banding at Lacreek National Wildlife Refuge

USFWS Migratory Birds
5 min readNov 1, 2021

By Terry Liddick

Four swim-in traps in a lake that have about 10–15 ducks caught in them
Swim-in traps with ducks. Credit: Phil Thorpe/USFWS

The waterfowl banding season in southwest South Dakota started this year much like it did in 2020 — another year that the pandemic prohibited us from going to Canada to our traditional banding locations. However, it was quite different than 2020 as the prairies of North and South Dakota have been descending deeper into drought since last spring. On August 2nd, I began a series of flights to do some reconnaissance looking for concentrations of ducks at each of the four banding locations we were going to this year, two in North Dakota and two in South Dakota. The reconnaissance flight over southwestern South Dakota near Lacreek National Wildlife Refuge and the surrounding area revealed significantly fewer wetlands, which means we had fewer areas where we could trap ducks. While we were disappointed about this, my hope increased when I began noticing significantly more visible ducks on the few wetlands that remained. This is common when wetlands diminish in drought years and often aids us because ducks will congregate, and concentrated birds are easier to trap. The story doesn’t end here, however.

Two biologists remove ducks from swim-in trap standing in water
Miguel Jimenez and Terry Liddick (R) emptying the swim-in trap into the catch box. Credit: Phil Thorpe/USFWS

Miguel Jimenez and I arrived in Valentine, NE on August 15th. This is the 4th time I had Miguel on my crew and I was glad to welcome him back. Each year, banding crews are filled out from volunteers throughout the U.S. Fish and Wildlife Service, who only need their supervisors’ approval to participate in this important detail. Our first drive around the area in southwest South Dakota to look at the areas I found from the reconnaissance flight confirmed that there were many mallards available, and the season looked as promising as last year. We spent another couple days looking to see where the ducks were concentrating, loafing, etc., and deciding where best to place our swim-in traps. On August 17th, with promising areas located and bait placed in those locations, we began setting traps. Within a few days, which it usually the time it takes for ducks to become acclimated to the traps being placed in the water, we began catching and banding ducks. That same evening, my colleague Phil Thorpe also arrived to fill out the crew and assist banding ducks for the month. This is about where the similarities and expectations from last year’s success began to change.

Closeup of a male wood duck
Male wood duck. Credit: Phil Thorpe/USFWS

We almost immediately began to trap good numbers of wood ducks and a handful of blue-winged teal. The wood ducks were not unexpected because we banded more than 160 wood ducks last year. As the days progressed, the wood duck numbers in our traps increased. However, we were not getting the mallards in the traps. Each day that we pulled up to each of our trap sites, many, many mallards were there but we were not getting any in the traps. This in itself is not worrisome early on as mallards are often the latest species to engage in the traps. However, as the days wore on, we continued to face the same situation; wood ducks in the traps and mallards flushing off as we pulled in. By the first of September, we also began catching larger numbers of blue-winged teal. This was also a little odd compared to last year as we only banded a total of 88 blue-wings. And so on it went, catching wood ducks and blue-winged teal, but flushing mallards.

One never knows for sure, but we may have discovered part of the problem with the lack of mallards in our traps on the evening of September 4th. We were driving around looking at other wetlands available that did not have high concentrations of ducks when we arrived a couple weeks earlier. There were still no ducks, but that had us heading home a little later in the evening than usual. We witnessed a large number of ducks, mostly mallards, and geese landing in a wheat field near one of our banding sites. The next morning, we looked at that field and it was loaded with waste grain. Upon inquiring about that field, we were told it was a hailed out winter wheat field that had been salvage harvested back in July. We watched the field again the next evening and witnessed the same event, large numbers of mallards and geese landing in the field for an evening feed. With this field being located between our three trapping sites, it appears there was plenty of food for the mallards so it out-competed the corn we were using for bait at our trap sites.

Every year is different, each brings its challenges and frustrations’, and we know and expect that, but the two years in southwest South Dakota could not have been more different. So with the lack of mallards in our traps, our primary target species, an increasing number of blue-winged teal in our traps and an increasing number of recaptured wood ducks in our traps that we had already banded, we began to make the decision to end the 2021 waterfowl banding effort.

A biologist holds a female hooded merganser and is showing the wing feathers
Female hooded merganser. Credit: Phil Thorpe/USFWS

By the 9th of September, we had a grand total of 29 mallards that we had applied bands to. Contrast that to last year when we had banded 1275. This year was significantly dryer than last due to the ongoing drought in the prairies. Last year we banded 164 wood ducks, this year we banded 475. Blue-winged teal were quite different as well, last year we only banded 88, this year 663. Maybe that is because of the lack of available water across the prairies, so more ducks were concentrating on the remaining wetlands. If that is the case, it certainly highlights the importance of our National Wildlife Refuges!

So as the sun set on the on the 2021 waterfowl banding season, I’ll continue to wonder. Was it the wheat field that provided the mallards all the food they needed or did the mallards just beat us this year. Was it the dry prairies that concentrated the teal and wood ducks or did we just not catch them last year? Regardless, the sights will be set on next year, with a hopeful return to our traditional banding locations in Canada to strategize and think once again on how to outsmart the ducks and trap and band them. Each year, the lessons learned from past years are applied and the challenges of the year at hand are confronted. As each banding season closes, the anticipation of the next begins. I’m already looking forward to it!

A biologist is holding a male wood duck and showing the feathers
Male wood duck wing. Credit: Phil Thorpe/USFWS

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USFWS Migratory Birds

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