Using Specialised Tunnels to Reduce Highway Mortality of Amphibians
Bibliographic record
Abstract
Previous studies identified roads as a source of habitat fragmentation and mortality for amphibians in Waterton Lakes National Park, Alberta, Canada, thus reducing the effects of roads became an important management issue. Vehicle traffic resulted in appreciable mortality of the Linnet Lake population of long-toed salamanders when adult and juvenile animals moved between this breeding site and terrestrial habitats. Tiger salamanders, western toads and red-sided garter snakes have also been killed by vehicles at this location. In spring 2008, drift fences and pitfall traps were installed for about 500 m along both sides of the Entrance Road that runs parallel to Linnet Lake to intercept and capture migrating amphibians attempting to cross the road. Road surveys were conducted daily before dawn for animals that evaded the fencing. Captured long-toed salamanders were marked with visible implant elastomer so a population estimate could be derived using a mark-recapture method and so that individual movement could be detected. Four specialised tunnels (AT500, built by ACO Wildlife) were installed in summer 2008 to allow long-toed salamanders and other small animals to cross safely under the road. Each tunnel is a box culvert 600 mm wide x 520 mm high. Each 1-m pre-cast segment was made of polymer concrete with slots that allowed air, moisture and light into the tunnel, creating a hospitable environment for amphibians. Segments were fitted together to span the width of the road (12 m), and set in concrete. Distances between tunnels varied from 80 m to 110 m. Installation took about two weeks; half of each tunnel was installed, traffic re-routed until the concrete set, then the other half was installed. The authors installed remotely-triggered cameras at the roof of each tunnel entrance to record animal movements. Cameras were set to detect motion and also to record images at fixed time intervals. The authors continued monitoring the population, movement patterns, and use of tunnels in 2009. In 2008 the authors captured 445 long-toed salamanders; the population was estimated at 1492 ± 214 adults. The authors also captured 15 tiger salamanders and 21 western toads. Two percent of long-toed salamanders (i.e., 10 of 445 individuals) travelling to or from Linnet Lake died on the road in 2008. Cameras photographed long-toed and tiger salamanders, western toads, and a variety of small mammals using the tunnels from 28 August to November 2008. Relatively few amphibians used the tunnels in 2008, because drift fences were still directing animals into the pitfall traps, and trapped animals were transported across the road. In spring 2009, fences were re-constructed to direct animals to the mouth of the tunnels, with one pitfall trap at the end of each tunnel. To 9 June 2009, 107 long-toed salamanders, moving both to and from the lake, have successfully navigated through the tunnels. Most images of the authors preliminary observations suggest that installation of drift fences effectively reduced road mortality and that the installation of road tunnels provides an effective and safe route of travel for a diversity of animals including long-toed salamanders. Monitoring via trapping and cameras promises to produce a meaningful assessment of the use of tunnels by amphibians and their effectiveness in reducing road mortality in Waterton Lakes National Park.
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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 | 0.001 | 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".