Isotopic (<scp>δ<sup>15</sup>N</scp> and <scp>δ<sup>13</sup>C</scp>) profiles in dentine indicate sex differences and individual variability in resource use among narwhals (<i>Monodon monoceros</i>)
Bibliographic record
Abstract
Abstract While the impact of ecological changes on Arctic marine mammals remains largely unknown, quantifying variability in resource use among conspecifics can serve as an indication of adaptive plasticity and help assess species vulnerability to climate‐induced changes. We measured within‐tooth δ 15 N and δ 13 C profiles of narwhals ( Monodon monoceros ) sampled 35 years apart from Baffin Bay, Nunavut, Canada, to evaluate intrapopulation variation in narwhal resource use. Narwhal dentine δ 15 N and δ 13 C were lower post‐1983 ( n = 7) by 0.83‰ and 0.52‰, respectively, compared to pre‐1983 ( n = 13), but isotopic niche breadth increased from 0.95‰ 2 to 1.12‰ 2 . Between sexes, the isotopic niche of males expanded from pre‐1983 to post‐1983 while that of females decreased, which may indicate increased flexibility in resource use for males and the opposite for females. Additional isotopic variation among narwhals ( n = 23) suggests individual differences in diet composition and/or foraging location during both periods. Individual isotopic niches ranged between 0.08‰ 2 and 2.27‰ 2 , where a larger isotopic niche likely indicates more variable foraging strategies over time. Narwhal as a species is considered vulnerable to ecosystem change; however, the variability in resource use between sexes and among individuals suggests narwhals may vary in their adaptability to changing Arctic conditions.
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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 | 0.006 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.003 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.015 |
| Research integrity | 0.000 | 0.001 |
| 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".