Demographics of Breeding Female Mallards in Southern Ontario, Canada
Bibliographic record
Abstract
Reliable estimates of breeding-ground demographic rates are needed to develop effective conservation strategies for mallard (Anas platyrhynchos) breeding habitat in eastern North America. We radiomarked 224 female mallards in an agricultural landscape in southern Ontario, Canada, during 1997–2000. At each of 4 sites, 1 during each year, we estimated survival of adult females, breeding incidence, nesting effort, clutch size, nesting habitat use, nest survival, and hen success. We also examined the influence of nest age, date, and habitat on nest survival and the influence of date and female age on survival of adult females. Almost all females remaining on site were observed to initiate ≥1 nest (x̄ = 0.97, range = 0.95–0.98), we detected a mean of 2.07 (1.80–2.36) nests per female each season, and full clutch size averaged 9.56 (9.1–10.0). For most sites, females nested in grassland and hay land more than expected relative to habitat abundance, nested in wetlands and woody habitats in proportion to abundance, and avoided cropland and developed areas. Survival of adult females from 25 March to 15 July averaged 0.75 (0.65–0.84). Estimates from our best model showed relatively uniform survival across the breeding season, with the exception of large decreases for 2 sites during the peak of the onset of hay cutting. Nest survival averaged 0.13 (0.11–0.15). Our best model supported increasing survival with nest age but did not include variation relative to habitat or date, except in hay land. Nest survival in hay land was high relative to other habitats early in the nesting season, but declined sharply with the onset of hay cutting. Hen success averaged 0.37 (0.25–0.46). Because estimated nest survival varied little among sites and habitats and because suitable nesting habitat appeared abundant, we suggest that upland habitat conservation will accrue only limited demographic benefits. Incentives to alter hay-cutting practices may decrease mortality of nests and nesting females, but we believe such incentives are unlikely to be cost efficient and that experiments would be needed to reliably assess benefits.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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 teacher head, 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".