The annual Waterfowl Breeding Population and Habitat Survey provides estimates of breeding waterfowl populations and habitat conditions across major breeding areas in the United States and Canada. Biologists count ducks and water bodies from aircraft, while ground crews provide information used to adjust the aerial observations.
The results help track waterfowl populations and inform hunting regulations, but they don’t necessarily predict hunting success. Weather and habitat conditions often have a greater effect on when and where waterfowl migrate, how many ducks hunters see locally, and the success of an individual hunt.
Here’s how ducks and ponds are counted, what the annual numbers mean for hunters, and what the results can and cannot tell us.
How are ducks counted?
The history of the survey goes back more than 60 years to an experimental aerial survey conducted by the federal agency that would later become the US Fish and Wildlife Service. Today, the survey is the largest of its kind in the world, spanning some 2 million square miles and involving teams of biologists from the USFWS, state and tribal wildlife agencies, and Canadian Wildlife Service.
The survey territory stretches across the northern breeding grounds from Maine to the Dakotas and Montana, and north into Canada’s Boreal Forest of the Northwest Territories and Alaska.
Beginning in May, teams of pilot-biologists and accompanying observers begin surveying waterfowl populations from the air across these key breeding areas. In all, twelve teams cover about 80,000 miles, primarily from fixed-wing aircraft flying treetop-high at roughly 100-miles-per-hour.
What do the observers record?
Both the pilot-biologist and an observer count waterfowl within a fixed distance from the aircraft. They record the species and social grouping, such as a single drake mallard, a pair of canvasbacks or a group of birds of the same species.
The observer also records the number of water bodies observed, separating them into categories of importance for breeding waterfowl. This allows the survey to provide an assessment of habitat conditions on the breeding grounds.
Why are ground crews used?
In areas of the Prairie Pothole Region, ground crews shadow the air crews and count birds in a similar fashion. Their observations provide a correction factor that can be applied to data collected from the air throughout the survey area.
Once the survey crews finish, the data are sent to USFWS offices in Laurel, Maryland. Biometricians work with the pilot-biologists and ground crews to verify the raw data before producing estimates for each region. Those regional estimates are then rolled into the final, complete report.
Why are ponds counted?
Pond counts provide information about habitat conditions on the breeding grounds. The survey records the number of water bodies observed and separates them into categories of importance for breeding waterfowl.
Ponds are important because they provide habitat for waterfowl during the breeding season. The number of ponds, along with other habitat conditions, helps biologists understand how well the breeding grounds may support nesting and young birds.
For mallards, the survey’s population estimates and pond counts are used in models that predict how many new birds will be recruited into the overall population. Pond numbers therefore, provide important context for estimating the fall flight and understanding annual changes in waterfowl populations.
What do the results mean for hunters?
In addition to population estimates for many dabbling and diving duck species, the Waterfowl Status Report includes a mallard fall flight index, which provides an estimate for the fall population of midcontinent mallards.
“We have a sizable amount of data on mallards, which we have used to develop models that allow us to take a given year’s abundance of mallards and number of ponds and predict how many new birds will be recruited into the overall population,” says Jim Dubovsky, retired from the USFWS’s Division of Migratory Bird Management.
“We can then add that number to the number of birds that we saw in the spring and output what the fall flight will be, and that will be used to help set season regulations.”
How do the numbers influence regulations?
The information gathered during the spring survey is used to set waterfowl hunting regulations for the following year. The spring survey, however, is just one of the tools used to develop harvest regulations.
Data collected through banding programs and harvest surveys are also vital to the process. Together, these three monitoring programs underpin so much of what managers do to set regulations and provide as much harvest opportunity for hunters as possible.
All the monitoring data are incorporated into Adaptive Harvest Management models. These models prescribe a liberal, moderate, or restrictive season structure for each flyway.
Federal officials, state waterfowl managers, and other members of the four flyway councils then meet to formally recommend hunting seasons and bag limits for the following season.
What can’t the numbers predict?
The annual numbers cannot directly predict:
- When ducks will migrate
- How many ducks a hunter will see locally
- Local wetland or food conditions
- Weather during the season
- Hunting pressure
- An individual hunter’s success
Mother Nature has a lot to say about when and where birds migrate. Weather and habitat conditions can have an especially significant effect on migration and distribution.
A high population estimate does not guarantee that ducks will move through a particular area or that a hunter will have a successful season. Those outcomes depend on conditions across the landscape and throughout the migration cycle.
How does Ducks Unlimited use the survey results?
The Waterfowl Breeding Population and Habitat Survey provides important scientific information that helps guide waterfowl conservation and management.
DU uses population trends, pond counts, habitat information and other scientific data to help identify conservation priorities. While DU cannot control rainfall, weather or migration, it can conserve and restore the wetlands and grasslands waterfowl need throughout their life cycle.
The survey helps DU and other conservation partners better understand where habitat conditions are changing and where conservation efforts can provide the greatest benefit.
How can I find the newest results?
The newest duck numbers are coming soon. Check back for DU’s complete species-by-species breakdown and scientific interpretation.
