Late Pleistocene heather vole, <i>Phenacomys</i>, on the North Pacific Coast of North America: environments, local extinctions, and archaeological implications
Bibliographic record
Abstract
Phenacomys cf. intermedius, the heather vole, is known from three late Pleistocene and early Holocene localities on Vancouver Island, British Columbia, Canada, where they are absent today. This study reports the heather vole specimens from one of these sites, P2 Cave, and provides a human behavioural context for its presence and eventual extirpation as a consequence of changing environments. Heather vole is a cold-adapted rodent. The early Holocene thermal maximum and subsequent development of coastal western hemlock forests contributed to its Vancouver Island extinction without an apparent corresponding range restriction in higher elevation habitats as has been noted elsewhere in Western North America. Tendency for low population densities in closed-canopy forests, antisocial intraspecies behaviours, and limited immigration across fragmented habitats supported local extinction. The absence of heather vole in the modern environment elsewhere along the coasts of British Columbia, Southeast Alaska, and Washington is probably due to similar factors as are highlighted here. Toward environmental reconstruction and the archaeological setting this study suggests that humans are unlikely to have occupied the Vancouver Island area during a hiatus in the vertebrate faunal record including the cold-adapted heather vole from about 19 700 to 14 700 years ago when the Cordilleran Ice Sheet extended west to the continental shelf. Improved environmental conditions for humans occurred both before and after this time. It also suggests that the glacial conditions in which the heather vole occupied Vancouver Island diverge from the Holocene interglacial setting that has seen an expansion of a human presence and of the corresponding archaeological record.
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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 | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 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".