Using stable isotopes of plasma, red blood cells, feces, and feathers to assess mature-forest bird diet during the post-fledging period
Bibliographic record
Abstract
Post-fledging use of early successional habitat by mature-forest birds is well-documented, but the important trophic factors driving this association remain poorly understood. We used stable isotope analysis of plasma, red blood cells, feces, and feathers to determine foraging preferences of three mature-forest bird species captured in 8-year-old clearcuts during the post-fledging period. We did not identify a significant source contribution in any consumer tissue combination using MixSIAR posterior distributions, but the position of consumer tissues in bivariate isotope mixing space suggested that all three mature-forest bird species acted as generalist insectivores during the post-fledging period. Furthermore, estimates of the proportional contribution of fruit to the overall diet were <0.13 for all Scarlet Tanager (Piranga olivacea (J.F. Gmelin, 1789)) tissue types, despite observational evidence of frugivory. We observed significant differentiation in core-niche-space estimates between the two obligate insectivores (Worm-eating Warbler (Helmitheros vermivorum (J.F. Gmelin, 1789)) and Ovenbird (Seiurus aurocapilla (Linnaeus, 1766))), suggesting that clearcuts provided adequate habitat to support the different foraging strategies and invertebrate preferences of both species. By using tissues with short turnover rates to address post-fledging trophic associations of mature-forest birds, we provide a comparison of isotopic values of multiple consumer tissue types in this context.
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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 | 0.000 |
| 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 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".