The eight species present puzzled Sexton and his colleagues, given a richer panorama in the county.
Islands in a sea of development
In retrospect, it became clear that floods over the centuries must have had a huge impact on species diversity there, Sexton said, adding that the island effect also plays a role. That is the situation most natural areas, including Yellowstone Park, contend with: They are islands in a sea of development on every side, thus limiting, if not eliminating, the migration of non-resident species to a site.
The third serendipity came about a few months after the 1993 flood waters receded. Sexton heard of a farmer upstream of Marais Temps Clair whose house and farmyard did not suffer flooding but had been completely surrounded by floodwater. The farmer removed 200 garter snakes alone that year found in his yard, machines, sheds and implements, and released them in safe areas.
The following year Sexton and his colleagues visited the farm and removed 55 snakes, three species of which they had not found at Marais Temps Clair, strong proof that they were displaced there by the flood. The evidence gave Sexton the idea of having a sanctuary for snakes and other species to wait out a flood. They would be like islands in a stream.
Think of it, to escape a flood, any kind of high ground can save lives, Sexton said. When you see all the soil that is moved to make a road, to build homes and malls, you think the soil has to be dispersed some place. If we could get a program together to reward contractors to bring that excess soil to flood-prone refuges such as Marais Temps Clair and pile up several mounds of earth that would be at least 15 feet above the top of the levees, wed allow more snakes and other species to survive future major floods and keep healthy populations at Marais Temps Clair.
I think of it as
|Contact: Tony Fitzpatrick|
Washington University in St. Louis