Species #10: Mississippi map turtle (Graptemys pseudogeographica kohnii)
Location: Trinity River (Dallas County, Texas)
Date: 23 April 2017
Species #11: Sabine map turtle (Graptemys sabinensis)
Location: Sabine River/Highway 69 (Wood County, Texas)
Date: 23 April 2017
Species #12: Texas cooter (Pseudemys texana)
Species #13: Texas map turtle (Graptemys versa)
Species #14: Common musk turtle (Sternotherus odoratus)
Location: County Line BBQ (Austin, Travis County, Texas)
Date: 23 April 2017
Species #15: Cagle’s map turtle (Graptemys caglei)
Location: Palmetto State Park (Gonzales County, Texas)
Date: 24 April 2017
Species #16: Pallid spiny softshell turtle (Apalone spinifera pallida)
Location: Harris County, Texas
Date: 24 April 2017
Species #17: Alligator snapping turtle (Macrochelys temminckii)
Location: Harris County, Texas
Date: 25 April 2017
Species #18: Texas tortoise (Gopherus berlandieri)
Location: Hidalgo County, Texas
Date: 26 April 2017
Species #19: Rio Grande cooter (Pseudemys gorzugi)
Location: San Felipe Creek/Highway 90 East (Del Rio, Val Verde County, Texas)
Date: 26 April 2017
Species #20: Mexican plateau mud turtle (Kinosternon hirtipes murrayi)
Location: Presidio County, Texas
Date: 27 April 2017
Species #21: Big Bend slider (Trachemys gaigeae)
Location: Big Bend Ranch State Park (Brewster County, Texas)
Date: 28 April 2017
Post by George L. Heinrich
Children watching turtles, a popular activity at County Line BBQ (Austin, Travis County, Texas). Photograph by George L. Heinrich.
Texas is big! Rich in land and habitat diversity, the Lone Star State is home to 30 species of turtles (50.8% of the diversity in the United States) and has more endemic taxa of chelonians than any other state. I recently joined herpetologist Carl J. Franklin (University of Texas at Arlington) for seven days of fieldwork which allowed us to observe 12 species in the wild. We traveled 2,430 miles by truck while exploring several river systems, parks, and preserves throughout Texas, as well as the ecologically rich Lower Rio Grande Valley and Big Bend region.
Almost immediately after I landed at the Dallas-Fort Worth Airport, we were on our way east to search for turtles. By day’s end, we had located five species: Mississippi map turtle (Graptemys pseudogeographica kohnii), Sabine map turtle (Graptemys sabinensis), Texas map turtle (Graptemys versa), Texas cooter (Pseudemys texana), and common musk turtle (Sternotherus odoratus). A long day on the road ending in Austin (Travis County) had advanced The Big Turtle Year species count to 13. The Texas map turtle is a state endemic and occurs in the Colorado River system from the central part of the state to nearly the Gulf of Mexico. Another endemic is the Texas cooter which occurs in the Colorado, Brazos, Guadalupe, Neuces, and San Antonio watersheds. Tim Walsh and I study another species in that genus, the Suwannee cooter (Pseudemys concinna suwanniensis), in Florida, so this was a species that I really wanted to see in the wild.
Mississippi map turtle (Graptemys pseudogeographica kohnii) basking on shoreline of the Trinity River (Dallas County, Texas). Photograph by George L. Heinrich.
Texas cooter (Pseudemys texana) swimming at County Line BBQ (Austin, Travis County, Texas). Photograph by George L. Heinrich.
George L. Heinrich with an adult male alligator snapping turtle (Macrochelys temminckii; Harris County, Texas). Photograph by Jordan Gray.
On day two, we observed a Texas cooter basking on the shoreline of the San Marcos River in Palmetto State Park (Gonzales County). A stop at a second location within the park got us our first two endemic Cagle’s map turtles (Graptemys caglei), both basking on the same log. Later that day, Carl and I observed a Pallid spiny softshell turtle (Apalone spinifera pallida) and a red-eared slider (Trachemys scripta elegans) at an undisclosed location in Harris County. Eric Munscher (Director of the Turtle Survival Alliance, North American Freshwater Turtle Research Group) joined us to set three hoop net traps baited with tilapia. This location is a new alligator snapping turtle (Macrochelys temminckii) study site for that research group and they have captured all size classes during past trapping sessions. The three of us, along with Jordan Gray (Turtle Survival Alliance), checked the traps early the next morning and found two large alligator snapping turtles waiting to be processed and released; the largest one weighed 88.4 pounds! Of note, this cool species can grow significantly larger and has a fleshy appendage on their tongue that allows them to lure for fish and other live prey. I greatly appreciate Eric and Jordan making it possible for us to observe these amazing animals in wild Texas. Now that the alligator snapping turtle has been split into three species, I still have two more to find within their respective ranges in Florida. I’m looking forward to joining Dr. Jerry Johnston (Santa Fe College) for an upcoming night snorkel trip to search for the Suwannee alligator snapping turtle (Macrochelys suwanniensis).
Basking pallid spiny softshell turtle (Apalone spinifera pallida; Harris County, Texas). Photograph by George L. Heinrich.
Adult male alligator snapping turtle (Macrochelys temminckii; Harris County, Texas). Photograph by George L. Heinrich.
Eric Munscher, Carl J. Franklin, and Jordan Gray weighing an adult male alligator snapping turtle (Macrochelys temminckii; Harris County, Texas). Photograph by George L. Heinrich.
George L. Heinrich with a large juvenile Texas tortoise (Gopherus berlandieri; Hidalgo County, Texas). Photograph by Carl J. Franklin.
The next day found us in the Lower Rio Grande Valley (Hidalgo County) searching for a Texas tortoise (Gopherus berlandieri) with herpetologist Mayra Oyervides. Only a single, large juvenile specimen was located, but that was enough to get us species #18. This smallest of the six species of North American tortoises also occurs in Tamaulipas, Mexico. Fully protected by Texas law, it remains threatened by habitat loss, agricultural practices, road mortality, and entanglement in fences. The construction of any barriers, such as walls or fences, along the United States-Mexico border would be detrimental to the Texas tortoise, as well as many other species of turtles and wildlife.
Rio Grande cooter (Pseudemys gorzugi) habitat within golf course along San Felipe Creek (Del Rio, Val Verde County, Texas). Photograph by George L. Heinrich.
A visit to two locations on San Felipe Creek in Del Rio (Val Verde County) produced species #19, the Rio Grande cooter (Pseudemys gorzugi). This beautiful, rather small cooter occurs in lakes and small rivers in the Rio Grande River system, as well as waterways associated with the Pecos River. Unfortunately, populations of this species have been severely reduced.
Basking Rio Grande cooters (Pseudemys gorzugi) at San Felipe Creek (Del Rio, Val Verde County, Texas). Photograph by George L. Heinrich.
Adult female red-eared slider (Trachemys scripta elegans) at San Felipe Creek (Del Rio, Val Verde County, Texas). Photograph by George L. Heinrich.
Mexican plateau mud turtle (Kinosternon hirtipes murrayi) habitat (Presidio County, Texas). Photograph by George L. Heinrich.
The small Mexican plateau mud turtle, also known at the rough-footed mud turtle (Kinosternon hirtipes murrayi), our species #20, is one of the rarest turtles in the United States. Most of this species range is in Mexico and only a small population is located just north of the border in west Texas. Of all the Texas species that we targeted, this was the one that I was most excited to see in the wild. Management practices by private landowners (~96% in Texas), water issues, and a very limited range are all significant threats to this species. Little is known about the Mexican plateau mud turtle in the United States and increased field studies and conservation efforts are urgently needed.
Basking Mexican plateau mud turtle (Kinosternon hirtipes murrayi; Presidio County, Texas). Photograph by George L. Heinrich.
A visit to the Big Bend region of west Texas also provided an opportunity to observe Big Bend sliders (Trachemys gaigeae) in the Rio Grande River. Formerly considered a subspecies of the common slider (Trachemys scripta), populations of this attractive turtle have been depleted by collectors. I was stunned by the beauty of the Rio Grande River, particularly in the Big Bend region.
Carl J. Franklin searching for Cagle’s map turtles (Graptemys caglei) at Palmetto State Park (Gonzales County, Texas). Photograph by George L. Heinrich.
I want to end this post by saying that Carl's knowledge of Texas turtles is immense and he clearly delivered for The Big Turtle Year. To learn more about Texas turtles, please visit Carl's website: www.texasturtles.org. We have invited Carl to write a guest blog about Texas turtles and hope to be able to post that along with some of his photos soon.
With the species count now standing at 21, The Big Turtle Year next travels to California to locate two species, the western pond turtle (Actinemys marmorata) and Mojave desert tortoise (Gopherus agassizii). Stay tuned for more!