Isotopic (δ<sup>15</sup>N and δ<sup>13</sup>C) evidence for intersexual foraging differences and temporal variation in habitat use in waved albatrosses
Bibliographic record
Abstract
Waved albatrosses ( Phoebastria irrorata Salvin, 1883) forage close to their breeding grounds on Isla Española, Galápagos, during the short chick-brooding stage and make long trips to the Peruvian upwelling during incubation and chick rearing. Previous studies have suggested foraging segregation by sex: females spend more time searching than males do while foraging in the Galápagos Marine Reserve (GMR), and band recoveries suggest higher bycatch vulnerability of males in the Peruvian upwelling. We used stable isotope analysis (δ15N and δ13C) of whole blood of adult male and female albatrosses to test for intraspecific foraging segregation in this sexually dimorphic species. Analysis of serial blood samples revealed higher δ15N values in males, suggesting consumption of prey items of higher trophic level. We also detected seasonal variation in foraging ecology, with higher δ15N values at the beginning of the breeding season. Sex and regional differences in δ13C values were not significant, reflecting primarily pelagic foraging sites of both sexes, both in the GMR and the Peruvian upwelling. Our results provide evidence of trophic segregation, suggestive of competitive exclusion, and novel information on marine isoscape values in the Eastern Equatorial Pacific.
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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 | 0.001 |
| 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".