Turtles and Time: Juniata Biologist Records Oldest Known Blanding's Turtle
(Posted June 7, 2016)
HUNTINGDON, Pa. -- Turtles are slow. It takes them a long time to do things. They get it. That's why biologists can study turtles over decades by capturing individuals every few years to monitor their growth, travel habits, sex lives and other factors over long periods of time.
Very long periods of time. Ask 3R11L, who was first captured on the E.S. George Reserve, located about 20 miles north of Ann Arbor, Michigan. In 1954.
Roy Nagle, director of environmental health & safety and a wildlife biologist at Juniata College, recently re-caught a Blanding's turtle named 3R11L (biologists don't name their study subjects, no matter how cute or how old) May 23 as part of a long-term survey of Blanding's turtles, painted turtles and snapping turtles that live within the Michigan Reserve.
"The turtle had first been recorded in 1954 and based on its size was a minimum of 20 years old," says Nagle, who, with Justin Congdon, professor emeritus of ecology at the University of Georgia, has studied turtle life on the Reserve since 1987. "We saw her about a dozen times between 1987 and 2006 and caught her again this year."
"When you're handling these turtles, you feel like you should be gentle and take great care because you have this amazing creature in your hand."
Roy Nagle, Juniata biologist
The 2016 re-acquaintance between Nagle and 3R11L means that the respected old reptile is at least 83 years old -- the oldest recorded Blanding's turtle ever seen. Nagle only recently returned to the Michigan Reserve after studying the area's native population of turtles every summer between 1987 and 2006. Nagle and his fellow researchers Congdon and Owen Kinney, an environmental science teacher at Darlington School in Rome, Georgia, agreed to do a follow-up population study of the turtles for the University of Michigan 10 years after the research team wrapped up their long-term study in 2006.
"We have records of all the turtles that were recorded for the study from 1954 onward," Nagle explains. "The first study on turtles in the area was done by Owen Sexton, then a graduate student, and has been followed by different researchers for more than 60 years."
The venerable turtle 3R11L was caught in a large, net hoop trap baited with a pig heart purchased from a butcher's shop and marinated in sardine "juice." The trap is a series of netted hoops that allow the turtles to swim into the trap but makes it hard to escape.
Nagle worked with two research assistants, his son Elijah, a 2016 Juniata graduate, and his son Aidan, a sophomore at Juniata. Together with Congdon and Kinney, they caught and marked more than 250 turtles during this most recent visit in May. Each turtle is marked by notching their shell and with a dab of paint if a female turtle is carrying eggs.
What did they discover about good old 3R11L? How about that she is possibly gravid, which is reptile lingo for "pregnant"?
Although humans would raise an eyebrow and possibly more at the thought of carrying offspring at age 83, in turtles it may not be uncommon. Blanding's turtles do not reach sexual maturity until ages 14 to 21. After that, they can lay eggs well into old age.
"We found in our original study that the oldest females lay more eggs more often than 20 to 40-year-old turtles," says Nagle who worked on the project from May 20 to May 31. "We also think that the oldest turtles can learn, such as where to find food, where to find mates and how to avoid potential predators. These turtles probably live longer than the biologists who study them."
Nagle will continue to study the turtles of the George Reserve, at least as long as he can find research funds to allow him to observe the comings and goings of Blanding's (and other species).
"When you're handling these turtles, you feel like you should be gentle and take great care because you have this amazing creature in your hand," Nagle adds.
Contact April Feagley at firstname.lastname@example.org or (814) 641-3131 for more information.