Reptiles in danger: Implications of road mortality in wetlands of South America

Abstract

Undoubtedly, roads produce negative effects on wildlife, but when they are laid across wetlands effects can be exacerbated. The “hyperfragmentation” and loss of terrestrial and aquatic habitats generated by roads makes it urgent to measure effect on wildlife. Reptiles are highly susceptible to road mortality mainly because of their slow movement, and the use of roads as a substrate for thermoregulation and feeding areas. Here, we analysed reptile road mortality in the floodplain of the Paraná River (Argentina) at three sections: North (NS), Centre (CS), and South (SS). We compared the richness and abundance of reptile roadkill species that use different habitats by means of monthly samplings. We found 464 roadkills encompassing 27 species (1 turtle, 2 lizards, and 24 snakes). Despite a greater richness of terrestrial species, roadkill abundance was always dominated by aquatic species. We detected two hot spots of reptile roadkill where routes cross the Paraná River floodplain and the environment quality was high: one in the NS, located in a protected area with records of two Vulnerable species; and another hot spot in the SS, which recorded roadkills that belonged to almost all inhabiting snake species and presented the highest roadkill abundance. A temporal ‘hot moment’ of reptile roadkill occurrence was detected during autumn in the SS. This study provides a baseline for delineating measures to prevent and mitigate reptile mortality, focusing on specific places, moments, and taxa in roads crossing wetlands in the Paraná River floodplain.