Curious case of the coastal tailed frog (ascaphus truei) near the northern extent of its range
Bibliographic record
Abstract
Ascaphus truei, an ancient species of frog, migrated into British Columbia, Canada, following the last ice age. A. truei is of conservation interest because forestry practices, and the associated infrastructure, may reduce habitat quality. There is also concern that a warmer and drier climate will change the distribution and abundance of this species. I used two genetic methods, microsatellites and next-generation sequencing, to compare the genetic diversity of A. truei from the northern extent of its range in British Columbia, CA to southern Washington, USA. Both methods suggested a dramatic reduction in diversity across the northern portion of the species’ range. The phylogeography suggests a northern range expansion from a single refugium. I used DNA metabarcoding to compare the gut contents of larvae across three stream reaches and two development classes near the northern extent of A. truei's range. Gut contents differed between stream reach but did not differ among development class. Wetted width and ultimately stream volume may influence differences in gut content among stream reaches. I also quantified the relationship between an index of larvae density and environmental factors hypothesized to influence population density near the northern extent of the range. I assessed the segregation of larvae at various developmental stages. Wetted width and wetted depth correlated with differences in the abundance of larvae. Older developmental stages were captured in stream reaches with greater slopes than younger stages. Management should minimize modifications of stream structure, such as in-stream siltation due to road building. We should maintain habitat connectivity and gene flow to ensure the continued migration and adaptive capacity of A. truei.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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 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".