Evaluating the use of marine subsidies by Arctic foxes without direct coastal access; insights from stable isotopes
Bibliographic record
Abstract
Abstract The trophic structures of tundra ecosystems are often viewed as a result of local terrestrial primary productivity. However, other resources can be brought in through long-distant migrants or be directly accessible in coastal areas. Hence, trophic structures may deviate from predictions based on local terrestrial resources. The Arctic fox ( Vulpes lagopus ) is a small canid that may use marine resources when available. We used stable isotope values in Arctic fox fur and literature data on potential prey to evaluate Arctic fox summer resource use in a mountain tundra without coastal access. The dietary contribution of local prey, presumably mostly rodents, declined with declining rodent abundance, with a subsequent increased contribution of migratory prey relying on marine resources. Stable isotope values did not differ between this terrestrial area and an area with direct coastal access during years of high rodent abundance, but isotope values during low rodent abundances suggested less marine input than in a coastal population feeding primarily on marine prey. Our study shows that marine resources may be used by animals in areas without any coastal access, and we highlight that such partial coupling of ecosystems must be included in the modeling and assessments of tundra environments.
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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 | 0.000 | 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 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".