Fig 1.
Mitigation measures completed during the fall of 2012 along Highway 69/400 in central Ontario, Canada.
These measures include reptile fencing consisting of a heavy gauge plastic geotextile extending 0.8 m above- and 0.2 m below-ground with a 0.1 m wide lip running perpendicular underground (A). The fence was affixed to a 2.3 m tall large mammal, wire fence and was installed in areas believed to pose a risk to reptiles (B). Three ecopassages were built within the fenced area and each consists of two 3.4 m x 2.4 m x 24.1 m concrete box culverts (C), separated by a 15.3 m gap for increased light (D).
Table 1.
Number (proportion) of reptiles, alive (AOR) and dead (DOR), observed on the road between samples periods (Before, After) and sites (Control, Impact).
Fig 2.
Daily abundance of reptiles on the highway for each survey period (Before and After) did not differ for turtles (A), but did differ for snakes (B) when considering survey sites (Impact (●) and Control (○)).
The parallelism between the solid and dashed lines visually represents no significant interaction between site and period for turtles (A; GLM z488 = -0.05, p = 0.57), while this interaction was significant for snakes (B; GML z488 = 3.60, p < 0.01). Yet, a strong reduction in snake abundance at the Impact site was still not seen between periods, thus the interaction is due to the large increase in snake abundance observed at the Control site during the After period.