Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (<i>Ursus spelaeus</i>)
Bibliographic record
Abstract
The proposed dietary pattern of extinct Late Pleistocene cave bears (Ursus spelaeus Rosenmüller, 1794) has become controversial, as some authors have suggested that they were strictly vegetarian, whereas others maintain they were omnivores that at times ate large amounts of animal protein. We evaluated these alternatives by compiling stable isotope data of carbon (δ 13 C) and nitrogen (δ 15 N) from the bone collagen of adult European cave bears from the Late Pleistocene (Marine Isotopic Stage 3). The data include previously published analyses and additional data from the southeastern European (Carpathian) sites of Cioclovina, Muierii, Oase, and Urşilor. The cave bear isotopic values from bone collagen were compared with those from hair keratin occurring in grizzly bears (Ursus arctos horribilis Ord, 1815) collected from 1989 to 2009 in the western United States (Yellowstone National Park). The Yellowstone bears have access to a wide diversity of plants and animals, such that their diets can range from vegetarian to carnivorous. Thus, there was considerable δ 13 C and δ 15 N variation among the grizzly bear isotopic values, and the cave bear isotopic variation was encompassed within the overall grizzly bear isotopic distribution. More importantly, the δ 15 N distributions, reflecting principally trophic level, were not different between the cave bears and the grizzly bears; the cave bear values are, on average, slightly higher or lower than those of the grizzly bears, depending on the criteria for inclusion in the comparisons. It is therefore no longer appropriate to view Late Pleistocene cave bears as strictly or even predominantly vegetarian but as flexible omnivores within their diverse communities.
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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 | 0.001 | 0.001 |
| 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
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".