The scientist who uncovered the hidden nutrient reserves that fuel bird reproduction and migration
It's 1974 on the remote coast of Hudson Bay, Canada. A young scientist kneels in the Arctic tundra, carefully examining a Lesser Snow Goose. Most researchers at the time believed birds simply found all the food they needed for reproduction in their environment. But C. Davison "Dave" Ankney suspected there was more to the story—he thought these birds carried their own hidden supplies, much like a hiker carries provisions for a long journey. This simple but revolutionary idea would transform our understanding of avian biology and establish Ankney as one of the most influential waterfowl ecologists of his generation.
Dave Ankney dedicated his life to understanding the hidden lives of birds. His work took him from the marshes of Michigan where he grew up duck hunting to the harsh Arctic landscapes where geese breed.
Beyond his scientific contributions, Ankney was known for his fierce dedication to mentoring students and his love of spirited scientific debate—often accompanied by copious amounts of beer 3 .
Before Ankney's pioneering work, most scientists assumed that breeding birds gathered all the resources they needed for egg production from their immediate environment. The prevailing thought was that birds simply ate whatever was available near their nesting sites to form eggs and sustain themselves during reproduction.
Ankney challenged this conventional wisdom through his detailed study of Lesser Snow Geese. He discovered that female geese actually build up substantial fat and nutrient reserves before arriving at their breeding grounds, and these internal reserves—not just local food availability—largely determine how many eggs they lay and how successfully they incubate them 3 .
His research revealed something even more surprising: during the critical periods of egg-laying and incubation, the geese fed very little, if at all. This finding was initially so controversial that one of his early papers was nearly rejected by a prominent journal. Fortunately, the editor recognized its significance and published what would become a "Citation Classic" paper that has been cited by nearly 600 subsequent studies 3 .
Comparison of traditional understanding vs. Ankney's discoveries about nutrient reserves in birds
| Research Method | Application in Ankney's Work | Scientific Purpose |
|---|---|---|
| Body Composition Analysis | Measuring fat and protein reserves in geese | Quantify energy stores available for reproduction |
| Field Observation | Monitoring feeding behavior during nesting | Determine reliance on local food sources |
| Clutch Size Monitoring | Tracking number of eggs laid by individual geese | Correlate reproductive output with nutrient reserves |
| Laboratory Analysis | Examining physiological changes in captive birds | Understand mechanisms of nutrient transfer |
Ankney's research methodology combined grueling Arctic fieldwork with careful laboratory science. For his doctoral research, he spent extensive periods in the Canadian Arctic studying Lesser Snow Geese. His approach was both simple and rigorous: he carefully documented the body condition of geese when they first arrived at their breeding grounds, then tracked how these reserves changed throughout the nesting period 3 .
He discovered that geese arriving with more substantial fat reserves laid larger clutches of eggs. Furthermore, he found that females needed to retain some reserves after egg-laying to survive the incubation period, when they fed very little. This represented a sophisticated trade-off between reproduction and survival—geese had to balance using their reserves for producing eggs against saving enough for their own maintenance 3 .
Ankney's work demonstrated how careful observation could challenge long-held assumptions in ecology. His scientific toolkit wasn't filled with expensive technology, but rather with patience, rigorous methodology, and a willingness to question established theories.
Perhaps his most important contribution was establishing the concept of nutrient reserve dynamics—the study of how animals store and allocate energy for different life processes. This framework has since been applied to countless bird species and other animals, helping scientists understand the invisible resources that fuel migration, reproduction, and survival 3 .
Ankney extended this work to other species, including Brown-Headed Cowbirds, where he and colleague Dave Scott discovered how female cowbirds achieve remarkable fecundity—laying up to 40 eggs in an eight-week breeding season. Their research showed that cowbirds had modified their laying cycle in ways surprisingly similar to domestic chickens, demonstrating how evolutionary pressures could shape physiology across very different species 3 .
Discovered birds carry internal energy stores for reproduction
Found geese feed little during nesting periods
Identified reproduction vs. survival balance in birds
Extended findings to cowbirds and other species
| Research Finding | Traditional Understanding | Ankney's Discovery |
|---|---|---|
| Source of egg nutrients | Mostly from local environment | Primarily from pre-stored reserves |
| Feeding during nesting | Assumed to be regular | Minimal during egg-laying and incubation |
| Clutch size determinant | Food availability at breeding site | Fat reserves carried to breeding site |
| Female survival strategy | Not specifically studied | Required conservation of some reserves |
While Ankney made his mark with fundamental research on nutrient dynamics, he also waded directly into pressing conservation issues. He became particularly known for his work on two controversial topics: the decline of American Black Ducks and the overpopulation of Snow Geese.
When American Black Duck populations began declining, many hunters pointed to overhunting as the cause. Ankney's research told a different story. Through careful study, he demonstrated that the decline was primarily due to hybridization and competition with Mallards. His work showed that Black Ducks and Mallards weren't genetically distinct enough to maintain separate species boundaries when they came into contact, and Mallards were outcompeting Black Ducks in shared habitats 3 .
Ankney's research on population dynamics of waterfowl species
Even more controversial was his position on Snow Goose populations. In the 1990s, he published a paper titled "An embarrassment of riches: Too many geese" that challenged sacred cows of wildlife management. While most conservation efforts focused on increasing waterfowl populations, Ankney presented evidence that midcontinent Snow Goose populations had grown so large they were destroying their own Arctic breeding grounds through overgrazing 3 .
He argued for increased hunting of these geese—a position that initially shocked many conservationists but was eventually adopted as official policy when the Migratory Bird Treaty was amended to allow population control for conservation purposes. This demonstrated Ankney's commitment to following science even when it led to unpopular conclusions 3 .
Ankney wasn't just known for what he discovered, but how he engaged with the scientific process. Colleagues and students remembered the trepidation they felt when presenting research with Ankney in the audience. He was quick to challenge faulty logic, suspect assumptions, or sloppy thinking of any sort. As one colleague noted, "You learn more from arguing with someone than you do from nodding your head in agreement" 3 .
This love of rigorous debate became so central to his identity that when friends organized a retirement celebration, "every presenter made reference to Dave's love of debate (most also to the copious amounts of beer that so often lubricated such discourse)." These animated discussions occurred in diverse settings—from university classrooms to duck blinds, fishing boats, and research stations 3 .
Dave Ankney's impact extends far beyond his own research publications. During his career at the University of Western Ontario, he supervised 29 M.Sc. students, 14 Ph.D. students, and 4 postdoctoral fellows, in addition to mentoring countless undergraduates. Former students recall how his rigorous criticism—though initially intimidating—ultimately made them better scientists 3 .
Perhaps the most fitting tribute to Ankney's legacy is the Dave Ankney and Sandi Johnson Graduate Research Scholarships, established to support future generations of waterfowl researchers. These scholarships, awarded annually to one M.Sc. and one Ph.D. student, ensure that Ankney's commitment to rigorous science and mentorship will continue to shape the field he loved 3 .
| Year | Achievement | Significance |
|---|---|---|
| 1974 | Completed PhD at University of Western Ontario | Began academic career at same institution |
| 1981 | Elected as Elective Member of AOU | Recognition by ornithology peers |
| 1992 | Became AOU Fellow | Elevated to highest category of membership |
| 1997 | Received Ducks Unlimited Conservation Achievement Award | Acknowledgement of applied conservation work |
| 1999 | Ontario Federation of Anglers and Hunters Professional Conservation Award | Recognition by hunting conservation community |
| 2002 | Retired as Distinguished Research Professor | Culmination of 28-year academic career |
When Ankney passed away from cancer in 2013 at his marsh-side home in Long Point, Ontario, he was surrounded by his wife Sandi Johnson and his black lab Bug—a fitting end for a scientist who always remained connected to the natural world he studied. His work continues to influence how we understand the hidden resources that birds carry with them, and the delicate balance they strike between reproduction and survival 3 .