Migratory patterns of mallards in eastern North America as revealed from band‐recovery data
Bibliographic record
Abstract
Abstract Mallard (Anas platyrhynchos) distributions have changed in North America over the last century because of altered habitat and the direct augmentation of eastern populations with captive‐bred game‐farm mallards in the early twentieth century. Geographical overlap between wild and game‐farm individuals has resulted in interbreeding, with North American mallard populations now ranging from largely wild to more feral and feral x wild hybrids. How changing genetic integrity of North America's mallards translates behaviorally remains unknown. We analyzed band‐recovery data from 1949–2019 to estimate emigration rates and geographic distributions of mallards to understand whether the admixed genetic heritage of mallards in North America's Mississippi and Atlantic flyways resulted in variable autumn distributions. We included American black ducks (Anas rubripes) as a flyway migratory comparative, and analyzed datasets partitioned by flyway and major international space (i.e., Canada vs. United States). We present results that correspond to the hypothesis that western mallard populations of the 1950s expanded eastward and were the precursor populations of mallards in the Canadian provinces of the Atlantic Flyway, while mallards of the Atlantic Flyway in the United States showed substantially differing patterns. Specifically, we estimate that since 1990, approximately 23% of banded mallards on the United States side of the Atlantic Flyway are annually recovered in the Mississippi Flyway as compared to about 5% of those banded in Canadian provinces of the Atlantic Flyway. Given that mallards from the United States side of the Atlantic Flyway are considered a feral × wild hybrid swarm, annual westward emigration of 23% of these mallards is concordant with increasing prevalence of game‐farm mallard molecular variation detected in the Great Lakes and mid‐continent mallard populations. Our results provide insight into potential means for the movement of game‐farm molecular variation from the Atlantic into the Mississippi Flyway, and suggest that the effect of these mallards on the genetic integrity and future adaptive capacity of mallard populations in the Mississippi Flyway requires attention and consideration in future management decisions.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".