Pete Balfour of Ecorp tells me he has been studying Florida water snakes (a non-native speces) in the Folsom area. See this creature at:
Pete also has a Northern water snake, found in West Roseville on a mitigation site. See this beast at: http://www.fcps.edu/islandcreekes/ecology/northern_water_snake.htm
The issue for the Conservancy is that if either or both of these non-native snakes gets established in the Natomas Basin, it could be an aggressive competitor to the Conservancy’s giant garter snake. Exotic, introduced species usually have a deleterious effect on natives, and Pete thinks the results for these two snakes may be the same. That is, they could overwhelm the natives. He is currently working on a strategy to see what can be done with state and federal wildlife officials to address this threat. We offered the Conservancy’s hand in helping mobilize interest in Pete’s efforts. A worthy cause, Pete, keep at it!