By Garry Rogers

Arizona Turtles

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:  As they aged, Blanding’s turtles produced more eggs and offspring.  In some ways, the turtles became younger as they aged.  This reversal of reproductive success with age drew global attention from scientists and others interested in longevity and life extension.

Another interesting trait is resistance to toxic materials.  Arizona fish, frogs, and mollusks develop various forms of cancer in response to toxic chemicals in agricultural and 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 (Trachemys scripta) in the photograph is not an Arizona native.  It probably arrived as a pet sold by the roadside vendor who comes every summer and sells turtles at a highway intersection upstream from my ponds.  There are at least two pond sliders living here.  If humans wouldn’t empty the ponds, the pond slider might live at Coldwater Farm long after I’m gone.

(Just after I wrote the above, a visitor harvesting weeds for his sheep, accidentally backed his truck over the pond slider shown in the photograph, killing it instantly.)

Species of Arizona Turtles

• (From AZGFD, and Reptile and Amphibian Ecology International)
• World:  300
• United States:  59
• Arizona Turtles:  15
• Arizona Natives:  10
• Arizona Turtles at risk of extinction (S1-S4):  15
• ESA Arizona Turtles Listed Threatened:  2

Arizona Turtles References

• AZGFD (Arizona Game and Fish Department).
• Arizona Herpetological Association.
• Brennan, T.C.  2008.  Online field guide to reptiles and amphibians of Arizona.
• Congdon, J.D., A.E. Dunham, and R.C. van Loben Sels.  1993.  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.
• Stebbins, R.C.  1966.  A field guide to western reptiles and amphibians.  Houghton Mifflin, Boston, MA.  279 p.

Arizona Turtles Conservation Status Symbol Definitions

Symbols used by Arizona Game and Fish Department (AZGFD)

• S1         Critically Imperiled: Extremely rare or some factor(s) is making the species especially vulnerable to extirpation.  Typically 5 or fewer locations or very few remaining individuals (<1,000).
• S2         Imperiled:  Rare or some factor(s) is making the species very vulnerable to extirpation. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000).
• S3         Vulnerable:  Rare or found only in a restricted range (even if abundant at some locations), or because of other factors making it vulnerable to extirpation.  Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals.
• S4         Apparently Secure:  Uncommon but not rare, and usually widespread.  Usually more than 100 occurrences* and more than 10,000 individuals.  Possible long-term concern.
• E:          Exotic Origin:  Species is not native to AZ.

Symbols Used for the Endangered Species Act (ESA)
US Department of Interior, Fish and Wildlife Service

• LT          Listed Threatened:  Imminent jeopardy of becoming Endangered.
• PS         Partial Status:  Listed Endangered or Threatened, but not in entire range.
• C           Candidate:  Species for which the USFWS has on file enough information on biological vulnerability and threats to support proposals to list as Endangered or Threatened under ESA.
• C*         The Service identifies species for which they made a continued warranted-but-precluded finding.