Brazos Water Snake (Nerodia harteri)
Named after the mighty Brazos River herself, the Nerodia harteri, more commonly known as the Brazos Water Snake, are a friendly
resident of Texas rivers. This fish-eating snake is just one of species of interest considered threatened in the Brazos River basin.
The Brazos Water Snake is recognized as threatened by the Texas Parks and Wildlife Department and is protected by the Texas Parks and Wildlife Code.
The Brazos Water Snake has one of the most restricted ranges of any Texas snake, found only along the upper portions of the Brazos River drainage.
This includes the shorelines of Lake Granbury and Lake Possum Kingdom where observation rates hint at higher abundance than in riverine sections.
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The Brazos Water Snake is a mix of brown and gray or a green and brown combination. They can be identified by the four rows of dark dorsal spots that
run the length of its body, giving it a checkerboard appearance. The snake has a pink or orange-colored belly and its neck is often a yellow or cream color.
The Brazos Water Snake enjoys residing in water that is fast-flowing and rocky, and free of dense vegetation,
according to University of Texas Press research. This snake takes cover under rocks in water or in vegetation
along shore. Juveniles use medium to large, flat rocks on unshaded shores for hiding and rocky shallows for
feeding, while adults inhabit rocky riffles as well as a wider range of habitats in pools and lakes, according
the Journal of Herpetology.
Behavior and Diet
A day-time hunter, the Brazos Water Snake requires rocks within its habitat to provide cover and security. They typically eat small fish but have been recorded eating a variety of salamanders, frogs, and crayfish.
The Brazos Water Snake gives birth to as many as 23 live young between the months of September and October.
Ongoing Research/Conservation Efforts
Curent research includes a large project funded by the BRA and administered by Bio-West and Tarleton State in the
riverine sections of the Brazos above lake Whitney looking at distribution, habitat association, thermal
preference, snake fungal disease, and reproduction.
A sister project funded by the Texas State Comptroller’s Natural Resources Program awarded to Texas State University is doing similar research on the lake habitat sections as well as on the Conchos Water Snake in Colorado River basin reservoirs.
The Brazos River Authority under advisement of TPWD has committed to using stabilization rip-rap in the 6-8” range which produces smaller cavities conducive to the smaller bodied snake in our shore armoring projects.
The TPWD Conservation License Plate program (Conservation License Plate (conservationplate.org)) purchased material to increase habitat at Thorp Spring Park on Lake Granbury with labor provided by the BRA.
More research, conservation, and habitat protections are needed to better understand and protect this species into the future.
For more information on the Brazos Water Snake, go to:
- Conant, R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Second Edition. Houghton Mifflin Company, Boston, Massachusetts. xvii + 429 pp.
- Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.
- Scott, N. J., Jr., T. C. Maxwell, O. W. Thornton, Jr., L. A. Fitzgerald, and J. W. Flury. 1989. Distribution, habitat, and future of Harter's water snake, Nerodia harteri, in Texas. Journal of Herpetology 23:373-89.
- Tennant, A. 1984. The Snakes of Texas. Texas Monthly Press, Austin, Texas. 561 pp.
- Werler, J. E., and J. R. Dixon. 2000. Texas snakes: identification, distribution, and natural history. University of Texas Press, Austin. xv + 437 pp.
Read more about the other threatened species of interest here.