Reptiles
Brazos Water Snake
Nerodia harteri · also called Brazos water snakes
A slender, blotched snake hunts small fish along a rocky riffle on the Brazos River, found nowhere else on Earth, sharing its narrow, single-river existence with a close relative confined to a different Texas waterway entirely.
Overview
The Brazos water snake, Nerodia harteri, is a river-dwelling snake found naturally only within the Brazos River system of central Texas. Its extraordinarily narrow natural range, close relationship to the similarly restricted Concho water snake, and strong preference for flowing, rocky river habitat make it one of the more geographically distinctive water snakes in North America.
A single river, a single species
Few North American reptiles are tied as tightly to one specific waterway as the Brazos water snake, which exists nowhere in the wild outside the Brazos River system it calls home.
Status
Least Concern — locally stable within the Brazos River system of central Texas, though its single-river range keeps it more vulnerable to local disturbance than a widespread species would be.
Brazos Water Snake: common questions
Where does the Brazos water snake live?
This species exists naturally only within the Brazos River system of central Texas, making it one of the most geographically restricted snake species in the United States, found nowhere else in the wild.
How is the Brazos water snake related to the Concho water snake?
The two species are closely related Texas endemics, each confined to its own separate river system, the Brazos water snake to the Brazos River and the Concho water snake to the Concho and Colorado Rivers, and both share a similar preference for flowing, rocky riffle habitat over still water.
What is the main threat to the Brazos water snake?
Dam construction and reservoir management altering natural river flow patterns have historically posed the primary concern for this species, since these changes can eliminate the flowing, rocky riffle habitat it depends on for hunting small fish.
Is the Brazos water snake venomous?
No, like other North American water snakes, the Brazos water snake is non-venomous, though it may flatten its body, release a foul-smelling musk, or bite defensively if handled, behaviours that can cause it to be mistaken for a more dangerous species.