Ambystoma opacum produces one distinct burrow architecture: subvertical ramps.
Open burrows are used as temporary shelters to permanent dwellings. Burrows are subhorizontal (11-15 degrees) to subvertical (45-80 degrees) in orientation. Shafts, tunnels, and chambers are elliptical to circular in cross section (W/H ratio ~1.4) with irregular widths and heights along their length. The tunnel roof and walls curve outward and the floor is flattened. Shafts and tunnels are straight to curved. Chambers are the same height as the tunnels but ~1 cm wider. Burrow walls possess weakly formed, rounded to bilobate protrusions; these are impressions of the salamanders head and limbs produced during burrow construction.
Additional resources are available within the downloadable PDF and Excel files linked at the bottom of the page
Additional resources
Marbled Salamander Burrow Catalog (PDF)
Marbled Salamander Burrow Info Packet (PDF)
Marbled Salamander Burrow Data Spreadsheet (Microsoft Excel – Auto Download)