Ambystoma tigrinum produces five distinct burrow architectures: subvertical ramps, J-, U-, W-, and Y-shaped burrows.
Open burrows are used as temporary shelters to permanent dwellings. Burrows are subhorizontal (11-15 degrees), subvertical (45-80 degrees), to vertical (85-90 degrees) in orientation. Shafts, tunnels, and chambers are elliptical in cross section (W/H ratio ~1.8) 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. Burrow walls possess common, but intermittently spaced, rounded, elongate, or 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
Tiger Salamander Burrow Data Spreadsheet (Microsoft Excel – Auto Download)