EXPERIMENTAL EVIDENCE FOR THE COST OF POLYGYNY IN THE RED-WINGED BLACKBIRD AGELAIUS PHOENICEUS
Bibliographic record
Abstract
Abstract I examined the effect of harem size on female reproductive success in the red - winged blackbird (Agelaius phoeniceus) in Ontario while controlling for the confounding effects of territory and male quality. Male territories were matched by their quality and harem sizes were manipulated by selective removal of females. The removals created monogamous and bigamous harems. Bigamous females fledged significantly fewer young than monogamous females, mainly due to higher predation on their nests. Young of the bigamous females were fed less frequently than young of the monogamous females (mainly due to reduced male assistance), but the difference was not significant. There was a positive relationship between parental provisioning rate and nestling body size. Young of the bigamous females fledged at smaller body size than young of the monogamous females. Because fledgling body size is related to post - fledgling survival, young of the bigamous females presumably experienced lower survival than young of the monogamous females. The lower number of fledglings, combined with their lower survival, suggests that the bigamous females produced fewer descendants than the monogamous females. I conclude that polygyny is costly to females in this population of the red - winged blackbird. Previous experimental studies demonstrated that females in this population prefer to settle with unmated males rather than already - mated males. In light of the present findings, the preferences appear adaptive, as they reduce the cost of polygyny. In Pennsylvania, Searcy (1988) reported that females settle independently of harem size and that harem size has no effect on their reproductive success. A comparison of the Ontario and Pennsylvania populations suggest that there are geographic differences in the effect of harem size on both female preferences and reproductive success.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".