Geographic origins and genetics of eastern and Great Lakes mallards
Bibliographic record
Abstract
Abstract Eastern and Great Lakes populations of mallards ( Anas platyrhynchos ) have experienced a significant decline in recent years. These subpopulations are increasingly wild × game‐farm mallard hybrids because of widespread releases of game‐farm individuals. Concurrent with an increasing prevalence of releases, a near 50% decline in mallard populations in the United States occurred, while abundances remained stable in Canada. We aimed to refine our understanding of the metapopulation dynamics of eastern North American and Great Lakes mallards to provide information useful in population and harvest management. We used stable isotope and genetic techniques during pre‐hunting season (July–September) banding to determine if banding location was representative of hatch or molt origin of mallards and if wild mallards captured and banded had more northern origins than wild × game‐farm hybrids. Mallards are expected to be largely of local origin during the pre‐hunting season, but nearly 50% of our sample had an origin north of their banding site, suggesting substantial movements during the banding period. We detected a similar percentage of wild × game‐farm hybrid prevalence for the eastern mallard population (~89%), but a substantial increase in the Great Lakes region (~75%) compared to prior studies. However, we did not detect strong evidence for geographic or temporal variation in isotopic values (i.e., origins) of wild and hybrid mallards, which suggests that genotypes of mallards occurred together throughout the sampling period. Our results suggest that banding location of mallards in eastern North America does not equate to breeding ground origin or genotype (wild or hybrid), and we recommend investigation of other methods to understand if vital metrics differ among regions and genotypes. The movement we inferred during the banding season could potentially violate important assumptions that birds do not move among banding units and confound population vital rates estimated using banding returns. Thus, we recommend that current integrated population models consider eastern mallards as a single population because their movement throughout the banding period makes assessment at smaller geographic units invalid.
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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 | 0.000 |
| 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".