Fig. 2. Attributes of the physical environment along transects across a gravel road adjacent to a communal den of garter snakes (Thamnophis sirtalis parietalis) near Inwood, Manitoba. The graphs show mean values and associated standard errors for (a) reflectances, (b) vegetation cover on the ground, (c) canopy openness, and (d) incident solar radiation striking the ground. See text for explanation of methods. “Grass” and “gravel” refer to substrate types on different parts of the transect.