How adaptable are narwhal? A comparison of foraging patterns among the world's three narwhal populations
Bibliographic record
Abstract
How organisms will fare in the face of climate change depends on their behavioral adaptability to changing conditions. Adaptability in foraging behavior will be particularly critical as food web changes are already occurring in Arctic regions. Stomach contents from narwhals ( Monodon monoceros ) in the Baffin Bay (BB) population have suggested that narwhals are dietary specialists with little behavioral flexibility, but there are two other narwhal populations in the world, the Northern Hudson Bay (NHB) and East Greenland (EG) populations, of which very little is known about diet. We investigated whether plasticity in foraging behaviors existed among the world's narwhal populations and between sexes by comparing their stable isotope values and niches, and running stable isotope mixing models to determine primary prey. Stable isotope analysis was conducted on skin collected by Inuit hunters during their subsistent narwhal hunt in Canada and Greenland. Stable isotope analysis on carbon (δ 13 C) and nitrogen (δ 15 N) revealed the three populations have distinct stable isotope values that are not expected based on geographic differences and that males in all populations had significantly higher δ 13 C. Stable isotope mixing models revealed narwhals in EG forage more on pelagic prey, particularly capelin, while those in NHB typically forage in the benthos. Males, probably because of their size and enhanced diving ability, likely feed more intensively on benthic organisms, resulting in their higher δ 13 C. Stable isotopic niches were similar between males and females in each population, and between NHB and BB, but EG narwhals had a significantly larger niche, suggesting they either forage across a larger geographical expanse, or whales within the population employ individual dietary specialization. This is the first study to use stable isotopes to evaluate and compare diet in all three narwhal populations, which is vital for understanding how they will fare in the face of changing climate. We discuss how narwhal are adaptable in their preferred prey and how there is potential for narwhal to adjust foraging behavior in the face of the dramatic ecosystem shifts occurring with climate warming.
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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 | 0.000 | 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) | 0.001 | 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".