When protected areas are not enough: low-traffic roads projected to cause a decline in a northern viper population
Bibliographic record
Abstract
Animal mortality resulting from collisions with vehicles has emerged as a major human-caused threat to wildlife. While direct mortality of wildlife from vehicles has been well documented, fewer studies have focussed on the population-level effects of road mortality, particularly due to low-traffic volume roads. We conducted a population viability analysis (PVA) on western rattlesnakes Crotalus oreganus occupying a protected area with low road density and an average traffic volume of 350 vehicles d -1 , near the northern periphery of the species' range. We used the program Vortex with a field-derived database on road mortality, population demography, and extent of occurrence. The model showed that although the population had a high likelihood of persistence over the next 100 yr (extinction probability < 0.01), a substantial decline was projected (stochastic growth rate -0.035, 97% decrease in mean population size, from 2131 to 72) under the current road mortality rate (6.6% of population yr -1 ); any increases in road mortality rates were projected to cause extirpation in under 100 yr. Our study provides strong evidence that road mortality is and will continue to be a significant contributor to the decline of this threatened species, even without higher traffic volumes and other significant anthropogenic impacts.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.003 |
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; both teacher heads agree on what is shown here.
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".