The Home Range & Patterns of Wintering Mallards at WingSelect

Quality Wetlands & Minimal Disturbance

When waterfowl are provided with quality wetland habitats, without hunting pressure/disturbance, birds develop fairly predictable patterns from roosting, feeding, and resting areas. After several winters of observing and logging waterfowl movements on the farm, this winter (2022-23), I decided to map out spatiotemporal patterns of mallards using field and trail camera observations. I’ve worked to observe the daily movements of mallards on the property in detail to better understand their use of a wintering home range.

To build on the previous article regarding wintering fidelity/philopatry, these birds appear to be many of the same ones day after day, exhibiting nearly mirrored spatial & temporal patterns season after season. Without intense hunting pressure, we can control for the variable of hunting pressure within the immediate vicinity of the property. Our neighbors to the south do not duck hunt, so we have approximately 1000 acres of non-hunted wetland habitat on 3,000 contiguous acres of land.

Early to Mid-Season Observations

The map below shows the observed flight pattern of mallards at the farm from early November to around December 15th. Since we bought the property in 2007, mallards have typically used the moist soil unit (Sanctuary) in the southern part of the property first and then move to other units after food resources are exhausted. The roost, labeled “Roost #1,” has been the early and mid-season roost since we flooded the unit in 2015. Day after day, using trail cams and field observations, mallards arrive at the southern moist soil unit in the morning, feed heavily, and then utilize the adjoining buttonbush habitat and other adjacent mid to late-successional wetlands for midday resting/loafing. This time is used to preen, conserve energy, perform courtship displays, and other pair-bonding behaviors. Feeding continues throughout the day, but more intense feeding tends to occur at dawn and dusk. Approximately 20 to 30 minutes after sunset, birds leave in various-sized groups to Roost #1 and repeat the same sequence the following day. In 2022, this pattern lasted up until the majority of the moist soil seeds were eaten from the Sanctuary unit, which was around December 15th with the first trail camera sightings of birds on the Clear cut field on that date. The use of Roost #1 however lasted up until Christmas, while feeding locations shifted from the Sanctuary to the Clear Cut Field.

Early season patterns of waterfowl at the farm.

Mid to LATE-SEASON Waterfowl Observations

During the mid to late season, birds shifted their patterns to the moist soil unit labeled ‘Clear Cut Field’ in the map below. This shift in food sources was a result of diminished moist soil seeds in the ‘Sanctuary’ unit after several weeks of heavy feeding. The Clear Cut moist soil unit was planted in brown top millet and had a large amount of unutilized seed. During this time, roosting patterns continued with Roost #1, but gradually shifted over to Roost #2 until all of the mallards on the farm roosted in Roost #2 after Christmas.

This shift in roost use later in the season has occurred since observations began several years ago. I have developed a few hypotheses as to why the birds switch roost later in the season: 1.) The majority of perennial smartweed, beggarticks, and various other seeds in the roost unit are eaten to quantities below a foraging threshold. and/or 2.) As photoperiods approach the shortest length during mid-December, different groupings of mallards arrive on the farm that display different patterns.

Although perennial smartweed is not a desired plant in moist soil units (annual smartweeds are preferred by mallards), in years past when we hunted the property, gizzards removed from a significant portion of harvested mallards contained perennial smartweed seeds. It seems the birds consume millet, rice, etc. during the day and during the night they consume whatever seeds are available in the late successional roost habitat, which is typified by perennial smartweeds, buttonbush, bald cypress, arrowhead duck potato, and other mid to late-successional wetland plants.

Mid to late season patterns of waterfowl at WingSelect. Waterfowl began using the Clear Cut moist soil unit in mid-December, while still using Roost #1 up until Christmas. Based on field and trail camera observations, birds started using Roost #2 around December 20th until the majority of birds were using Roost #2 by Christmas.

Aerial photo of mallards feeding in the Clear Cut moist soil unit, December 2022.

Footage from 12-21-2022 in Clear Cut moist soil unit. Camera facing west with waterfowl leaving for roost heading Southeast to Roost #2 and heading northeast to Roost #1 during the transition period from Roost #1 to Roost #2.

Roost #2 - January 2023 - Approx. 30 minutes after sunset

What Can We Learn From These Waterfowl PAtterns?

The observation of these nearly mirrored patterns from year to year could imply that these are many of the same birds arriving each winter. These birds appear to have a strong memory of the landscape and where food & cover sources are located. If these are many of the same birds displaying site fidelity to these wetlands, this has major implications for hunting pressure & harvest.

If we hunted the farm heavily and harvested hundreds of breeding pairs, what kind of impact could this have on the returning population? Will reproductive rates on the prairie outpace the harvest rate of breeding pairs on this wintering home range? What about years when the prairie is experiencing extreme drought and nesting habitat is limited?

Before pulling the trigger this season, remember these birds are migratory, but they’re not '“passing through.” These birds have a strong homing instinct to return to their wintering grounds. Excessive disturbance and harvest could have lasting impacts on wintering waterfowl distributions & populations. Respect for the game is something we must not forget as hunters & conservationists. Limits don’t mean much when the skies are bare and the wetlands are quiet.