At least two turtle species live in my stock ponds near the northernmost stretch of perennial flow in the Agua Fria River.  I am sure Texas Spiny Softshells and Pond Sliders (photo) are present.  I think I saw a Sonoran Mud turtle, but the individual I saw might have been a small Pond Slider.

Turtles have exceptional regenerative powers.  Dr. Justin Congdon, a classmate from long ago, managed a study of turtles in the E. S. George Reserve in Michigan for more than 40 years. In the 1980’s Justin made a startling discovery:  Blanding’s Turtles were producing more eggs and offspring as they got older.  Eventually Justin published his results and drew international attention.

Related research shows that turtle cells live longer than cells of  most other vertebrates.  Learning how they do it might provide a means to add as much as 100 years to the average human lifespan.

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Another interesting trait of turtles is that they are resistant to toxic materials in their environment.  Arizona fish, frogs, and mollusks develop various forms of cancer in response to toxic chemicals from pesticides, urban runoff, and treated waste water.  Turtles do not.  Like other species groups, however, Arizona turtles suffer from habitat loss and human harvest.  The Pond Slider in the photo is not a native of the Agua Fria River.  It probably arrived as a pet sold by the roadside vendor who comes every summer and sells turtles at a highway intersection near the River.  There are at least two Pond Sliders living in my pond.  If the pond doesn’t dry up because of water pumping for urban use, the turtles may be living there long after I’m gone.

Field guides are provided online by the Arizona Herpetological Association and Thomas C. Brennan, and in print (Stebbins, 1966).

Turtle References

Arizona Game and Fish Department:  http://www.gf.state.az.us/.

Arizona Herpetological Association:  http://www.azreptiles.com.

Brennan, T.C.  2008.  Online field guide to reptiles and amphibians of Arizona:  http://www.reptilesofaz.com/.

Congdon, J. D., A. E. Dunham, and R. C. van Loben Sels. 1993a. Delayed sexual maturity and demographics of Blanding’s turtles (Emydoidea blandingii): implications for conservation and management of long-lived organisms. Conservation Biology. 7:826-833.

Partners in Amphibian and Reptile Conservation:  http://www.parcplace.org/.

Stebbins, R.C.  1966.  A field guide to western reptiles and amphibians.  Houghton Mifflin, Boston, MA.  279 p.

Checklist

*  Tier 1A species of greatest conservation need (Arizona Game and Fish Department).

** Indicates introduced species.