Most hunters are focused on what ducks and geese are doing during hunting seasons. We want to know when and where the birds are flying so that our hunts are successful. Outside of the days we spend in pursuit of waterfowl, many hunters are oblivious to the remainder of the migration. But it is the long-distance flights and instinct-driven decisions that these birds make throughout the course of an entire year—not just the small windows we are hunting them in—that really matter to the survival of the species.
That’s why scientists at Ducks Unlimited, several universities, governmental agencies, and private institutions are using innovative tracking technology to monitor the daily movements of waterfowl year-round. Small, solar-powered radio packs are being affixed to birds by conservationists across the country. The data from the tracking devices is offloaded when the ducks and geese fly within range of cell towers, using the same technology you do to scroll Instagram and send Snapchat “snaps” to friends from your smartphone.
Waterfowl are some of the most intensively studied animals on Earth, yet these new technologies are providing a level of detail about behaviors, movements, and biological linkages waterfowl managers previously only dreamed of. This information is allowing state wildlife agencies and federal organizations, such as the U.S. Fish and Wildlife Service, which sets season frameworks and bag limits, to better understand the needs of many waterfowl species.
Telemetry is Different from Bird Banding
If you’re a duck hunter, it’s likely you know about bird banding programs. If not, here’s how it works: Biologists will trap waterfowl either by baiting them into an enclosure they can’t escape from or using rocket nets, which shoot over a gathering of ducks or geese and capture them. The birds are then aged, sexed, marked with a uniquely numbered leg band, and released. Biologists use band data for a myriad of reasons, such as determining lifespan, survival rates, harvest rates, population status, and migration corridors.
But the key to obtaining this information requires the bands to be found. That only happens if a hunter shoots a banded bird and reports it, the band is found on a dead bird, or a banded bird is recaptured. And even then, a band can only deliver two data points—where the bird was banded and where it was shot, found, or recaptured. Everything else remains a mystery.
Telemetry studies allow biologists and scientists to track bird movements much more frequently. While telemetry units of various kinds have been used to study waterfowl for over half a century, the amount of data collected from modern devices is far greater than it ever has been. Today’s devices often record more than 1,000 locations per bird, along with mountains of additional data obtained from other sensors.
Just as with banding, birds are trapped or captured with bait traps, but in addition to a metal band, a solar-powered GPS telemetry unit is affixed, which weighs between 15 to 20 grams and attaches to the duck’s back with a backpack harness. Researchers have also developed implantable devices that are surgically inserted in the body cavity. These are typically used in diving waterfowl species so as not to hinder their ability to dive. Neck collar units for geese have been used for several years as well.
Before birds are released, they are weighed, and their bill, head, and leg bones are measured. Once the radio packs are deployed, a single person can monitor the birds from a computer in real-time (locations can be recorded at intervals ranging from one second to 48 hours). Data from the pack is sent to the nearest active cell tower, and even when a mallard flies out of cell service, the data is stored until it comes in range of a tower and is offloaded.
The transmitters are also outfitted with an accelerometer, so researchers can tell if the bird is resting, feeding, flying, or on the nest in the case of female ducks and geese. It’s a much more efficient way of collecting data than old VHF telemetry methods in which researchers had to be within a specified range of the birds. Scientists and their students had to physically drive or boat into the marsh with large antennas in the hopes that their birds were in range to collect data.
“The big question has always been, ‘What are these birds doing, and where do they go between breeding and wintering areas?’” said Dr. John Coluccy, director of conservation planning for DU’s Great Lakes and Atlantic region. “With this technology, we can answer those questions and many more. It also opens a whole new world for us as conservationists because we can focus our habitat work on the places where waterfowl need it most.”
Tracking Eastern Mallards
There are multiple telemetry studies being conducted at this moment, from tracking pintails in the Pacific, Central, and Mississippi flyways to monitoring the movements of Great Lakes mallards. But one of the most critical projects is focused on Atlantic flyway mallards, which have declined steadily since the late 1990s. There are actually two segments of Atlantic flyway mallards that are monitored annually: the Eastern Canada (Maine is included) population, which has remained stable, and the Northeastern U.S., which has fallen from just under 850,000 in 1999 to less than 500,000. That drop was significant enough to prompt the USFWS to cut the daily bag limit on Atlantic flyway mallards from four to two in 2019.
“There is no way to know what the status of the Eastern mallard population looked like before the 1990s because they were not being monitored,” Coluccy said. “We only know what’s going on right now, and it’s clear there has been a substantial decline in the Northeastern U.S.”
The study involves more than 20 organizations and is led by the New York State Department of Environmental Conservation, Pennsylvania Game Commission, University of Saskatchewan, State University New York-Brockport, and DU. It is in its second year of four and aims to deploy more than 1,200 transmitters on the backs of Atlantic flyway hen mallards. Data gleaned from this massive undertaking—the first of its kind in the flyway—will reveal not only where the ducks are nesting and wintering but the stops they make along the migration from Canada to as far south as South Carolina (you can track every deployed transmitter here).
“There are going to be millions of GPS locations that are produced as a result of this study,” said Josh Stiller, small game unit leader for the New York State DEC. “It’s going to help us identify some problem areas with Eastern mallards and better understand why we have seen such a decline in their population over the last 20 years.”
Why Is Telemetry Beneficial?
The data from the Eastern mallard study will help biologists identify factors contributing to the recent decline and prioritize the areas in which habitat improvements need to be made throughout the flyway. Then, state and federal conservation agencies can work with private organizations, like DU, to improve wetland quantity and quality on public land. This means targeting specific Waterfowl Management Areas and National Wildlife Refuges that are critical to mallards along the migration.
Moving dirt to create proper levee systems and updating water control structures and pump stations are some of the key ingredients as well. Proper infrastructure allows for timely water drawdowns so that natural duck food can grow. Then the water can be put back on the wetland in the fall as ducks arrive.
Wildlife agencies may also partner with non-governmental organizations (NGOs) to purchase land, restore it to native wetlands, and incorporate it into their public lands to increase access and opportunities for hunters and the general public. There are also numerous government programs like the U.S. Fish and Wildlife Partners for Fish & Wildlife and Farm Bill programs that provide cost-share for conservation work on private land. Many of these projects are focused on restoring marginal farmland to productive wetlands so that ducks and geese have more access to high-quality habitat.
“All you need to do is look at the 2022 State of the Birds Report and you will see that most waterfowl and other wetland-dependent bird populations are faring much better than other North American birds,” said Dr. Mike Brasher, senior waterfowl scientist at DU. “The population gains and current health of waterfowl are the result of responsible harvest management and decades of science-based planning and conservation in priority areas across each of the four flyways. While it’s certainly important to celebrate our past successes, it’s also critical that we continue to invest in impactful science and innovative conservation, as the threats facing waterfowl and their wetland and grassland habitats are only intensifying.”
