Data from: Benefits of an anti-parasite treatment are influenced by within-brood size variation in Tree Swallows (Tachycineta bicolor)
Bibliographic record
Abstract
In all animals, susceptibility to parasites can differ among individuals. Young, nest-bound birds are exposed to a diversity of nest-dwelling ectoparasites that typically feed on their blood. Within broods, hatching asynchrony creates size hierarchies that result in morphological and physiological variation among nest mates, and susceptibility to parasites also may vary predictably with this size hierarchy. Our objective was to use a broad-spectrum, anti-parasite drug, ivermectin (IVM), to treat individual nestling Tree Swallows (Tachycineta bicolor) and assess how nestling susceptibility to parasites varied both within and among broods. Broods were either assigned to an IVM group, where half of the nestlings in a brood received IVM injections and half received control injections of pure sesame oil, or to a control group, where all nestlings received oil injections. We found that the IVM treatment reduced parasite loads for broods as a whole, thereby benefiting all nestlings in IVM broods and suggesting our treatment resulted in herd immunity. Specifically, nestlings from IVM broods had higher hemoglobin concentrations, regardless of whether they received injections with IVM or oil, and greater fledging success, than nestlings from control broods. On the contrary, IVM treatment did not strongly affect nestling morphology, with only marginal effects on the growth rate of ninth primary feathers, and the effects of the treatment on 2 other morphological traits depending on temporal factors. Variation in size within broods, however, influenced the chance of an individual fledging, which increased with relative size within a brood, but only under lower parasite loads (i.e. IVM broods). By experimentally manipulating nestling susceptibility to parasites, we have demonstrated variation in nestling response to an anti-parasite treatment both within and among broods, and future studies should investigate the underlying mechanism for why certain nestlings along the brood size hierarchy are more susceptible to parasites.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.010 | 0.002 |
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".