Much of Kent’s work has focused on western Lucas County. Recently, though, his work has expanded to include Lake Erie marshes.
Photo: Kent Bekker
Turtles' relative long lives can mask their decline. “If you have a population of 10 turtles that lives to be 100 years old, but they’re only replacing one of those 10, you could be in real trouble without knowing it," Ken says.
Photo: Chris Hoving/flickr,
creative commons license
Measuring a turtle's shell can help determine its age. Very few of the turtles that hatch survive to maturity.
Photo: Kent Bekker
Zoo visitors can learn more about native turtles at animal feeds, demonstrations and encounters which run through Sept. 2. Native turtle feeds are part of the schedule.
Photo: Kandace York
Proceeds from on-grounds coin collectors, like this warthog in Tembo Trail, support Conservation Today. Selected Zoo merchandise also supports Conservation Today; look for displays in the North Star Trading Post® and KC's Corner Store (near Nature's Neighborhood).
Photo: Andi Norman
Why we care
Turtles are an ancient species. “They’ve basically remained unchanged for the last 300 million years,” Kent says. “They can live in conditions where most other animals could never survive.”
But wild turtle populations are declining. Of Ohio’s 12 native turtle species, two – Blanding’s turtles and spotted turtles -- are listed as threatened species. This means that, although they are not in immediate jeopardy, if their current threats continue or increase, they could become endangered.
Because turtles are so long-lived, it can take a while to notice population declines. As a result, by the time biologists realize what’s happening, it may be too late.
Kent gives an example. “If you see a Blanding’s turtle basking on a log, and 10 years later – or even 50 years later – you see one again, you might think their populations are OK. But that could easily be the same turtle.”
For stable populations, he says, "we need a 90 percent survival rate. Numbers are so low that if you remove even one from the wild, you may have just moved them from ‘viable’ to ‘not viable.’”
There’s even a term for this. “We call these ‘ghost populations’ because, although animals are still there, not enough of their offspring are surviving to replace them. They are functionally extinct.”
What we’re doing
Kent has spent the last eight years collecting data on native turtle species. Although that sounds like a long time to study one animal, he says it’s just the beginning. “Turtles are so long-lived that a good, long-term research project would take 50 years or more.”
He’s working with volunteers, staff and interns – and occasionally even Zoo campers – to catch turtles in humane hoop or funnel traps. They mark and measure the animals, then release them. Subsequent catch-recapture-release efforts are finding the same individuals from months or even years earlier.
Although Blanding’s turtles are the primary species the Zoo is working to help, Kent says all the animals he catches have something to offer.
“As scientists, often we just focus on species we know are in trouble,” he explains. “But what we’re doing now is compiling data on all the animals we find, to see if it can help us understand why common species are common.”
What we’re learning
One example of the things Kent has learned from this work is that turtles overwinter in unexpected places – like one particular ditch of western Lucas County.
“Through global positioning satellite (GPS) units that we had attached to the turtles’ shells, we narrowed down their locations to a space about 10 to 20 square feet,” he says. “We found three turtles overwintering in that space of the ditch. We also found their nests, and we know that the females are laying eggs.”
That sounds like great news. “But if someone comes along and dredges the ditch in, say, February, that whole population gets wiped out.”
Kent’s work has also indicated that reproduction rates among Blanding’s turtles are low; he rarely finds younger animals in his traps.
This is important because population declines can be harder to track in long-lived species. “There’s documentation that Blanding’s turtles live to be about 80 years old; they’re the longest-lived freshwater turtle species,” he says. “Because they live so extremely long, we need to be sure they are replacing their populations.”
The Conservation Today connection
The Zoo’s Conservation Today program is a donation-funded initiative that helps wild animal species, both locally and around the world. Native turtles, like the ones Kent is working so hard to help, are among the animals that Conservation Today supports.
The potential impact of this program is critical to future plans, Kent says. “Our hope is to continue monitoring them, quantifying the data we collect, and employing more GPS units on turtles. It will help us to know their critical habitats so we can better protect them.”
You can help
Your support of Conservation Today makes a big difference.
There’s even more you can do, though – and it may be easier than you think.
“If you see a turtle and can get a quick picture of it, we’d love it if you could email it to us,” Kent says. “The location where you found it, and the date, are also important. This helps us build a much larger database than if just a few Zoo employees and volunteers are collecting data.”
story by Kandace York
Aug. 29, 2013