Effects of Predator Management and Parasitism on Over-Water Nesting Diving Duck Production in Southwestern Manitoba
Bibliographic record
Abstract
Nest survival of upland nesting waterfowl (e.g., mallard [Anas platyrhynchos], blue-winged teal [Anas discors]) has been studied extensively in the Prairie Pothole Region (PPR) of North America. Conversely, over-water nesting diving ducks’ nest survival is poorly understood, likely because over-water nests are more challenging to find, may be less concentrated, and searching for these nests is physically demanding. Nest depredation is considered a leading cause of duck nest failure and is considered a limiting factor on upland nesting waterfowl production in the PPR. Similar factors limiting upland nesting duck production may limit over-water nesting duck productivity, but studies of this nature are lacking. Another limiting factor may be nest parasitism, an under looked attribute for some of these over-water nesting ducks (e.g., canvasbacks [Aythya valisineria]). Some species, particularly the redhead (Aythya americana), have adapted to habitat constraints by parasitizing other ducks’ nests. In previous studies, 30%–50% of canvasback nests were parasitized by redheads, with an average of 3 parasitic eggs laid per nest. For these studies we first evaluated the efficacy of predator trapping and removal on the survival of over-water duck nests of five focal species of diving ducks in Southwestern Manitoba. To further understand nest parasitism in diving ducks, we tracked host and parasitic eggs of redheads in canvasback nests in southwestern Manitoba, Canada, during the 2019 and 2020 nesting seasons. We counted all eggs found at host nest sites and classified eggs as successful, lost to parasitism, or depredated. Although mean nest survival was greater on traditional trapped sites, confidence interval estimates indicated an equivocal treatment effect. Thus, trapping predators had, at best, a modest positive influence on survival of over-water duck nests and did not generally appear to be an effective way to increase nest survival for these five focal species. We do, however, suggest that redhead parasitism may be a factor limiting canvasback productivity in our study area and deserves further investigation.
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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 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".