The world’s oldest known freshwater turtle turns 95 years of age this year. A female Blanding’s turtle, it sets a new record with each year of life. And this turtle doesn’t appear to be slowing down. In fact, she is still producing eggs, and shows no sign of declining with age.
“This past summer, we examined the turtle for all indicators of aging,” said researcher Justin Congdon, who studies the turtles during nesting season. “And we could find no discernible difference or indication that this turtle is aging. She can take off just as fast as the young turtles! She looks and behaves just like all the others. The turtle had 11 eggs, which is the exact average number of eggs for this habitat.”
The turtle, named 3R11L, lives at the University of Michigan's Edwin S. George Reserve (ESGR) located northwest of Ann Arbor, in Livingston County. First marked in 1954, 3R11L was considered an “adult” even at that time. Blanding’s turtles typically reach maturation between 14-20 years of age.
Since then, the turtle has been captured 70 times and is currently the oldest recorded Blanding’s turtle anywhere, outlasting the next oldest, a 76-year-old Blanding’s turtle in Minnesota. As for its senior citizen status, 3R11L is in good company. Three other female turtles on the reserve are also of advanced age, marked as at least 69, 70 and 73 years of age, respectively. In total, more than 1,600 adult turtles have been studies at ESGR at various times.Three species of freshwater turtles are present at ESGR, including Midlandpainted turtles (Chrysemys pictamarginata), Blanding’s turtles (Emydoideablandingii), and snapping turtles (Chelydraserpentina).
The turtle population and community composition have remained relatively stable over the recent decades, an encouraging indicator for conservation. However, invasive shrubs have overtaken historic nesting sites and are the focus of ecological restoration projects at the reserve. Additional threats include a proliferation of raccoons, which in some years consume most of the Blanding's’ eggs. Invasive purple loosestrife (Lythrum salicaria) is taking hold in the wetlands and may reduce hatchling recruitment.
“I find it fascinating that 90-year-old Blanding's turtles match the younger turtles in terms of reproduction,” said Dr. Chris Dick, Director of the ESGR. “We don't know why this is so, but it's possible that the youth of the younger turtles is balanced bythe better knowledge the older turtles possess. The older turtles know their environment well and have the ability to find more ponds and resources during periods of drought than the younger ones.”
This decadal study continues to reveal new insights into how this species and others are impacted by ecological changes. All of the data collected and some biological material are being curated at U-M's Museum of Zoology. This includes more than 5,000 X-rays and all master files, and an extensive blood and DNA repository, compiling one of the most comprehensive resources for freshwater turtles available anywhere.
