By Jessica Fliginger
Today, half of the world’s freshwater turtles and tortoises are threatened with extinction. Due to the alarming rate of turtle disappearance, they are now among the most threatened group of vertebrate animals on earth. Turtles play critical roles in maintaining the health of our food webs and losing them could have negative effects on our ecosystems.
In Illinois, Blanding’s turtles are listed as state endangered, making it illegal to possess or collect this species without the proper permit. Populations are in decline throughout their range, which extends from Canada and Novia Scotia, south into New England, and west through the Great Lakes to Nebraska, Iowa, and northeastern Missouri. In general, their populations are small, discontinuous, and often isolated. Blanding’s are long-lived turtles and can live up to 80 years. Females don’t reach sexual maturity until 14 to 20 years and have small clutch sizes ranging anywhere from 5 to 20 eggs. Based on this information, I’m sure you can gather that Blanding’s turtles, like most turtles, face a multitude of challenges in our human-dominated landscape where there are plenty of predators to avoid.
It’s extremely hard to have a bad day out on the prairie when I’m using radio telemetry to track Blanding’s turtles at Nachusa Grasslands. The "smile" they exude reflects their behavior; they are pleasant to handle and not at all aggressive, unlike snapping turtles I’ve encountered.
I have been fortunate to spend the past two years working as a Blanding’s turtle field technician for Professor Dr. Rich King in the Department of Biological Sciences at Northern Illinois University. In an effort to promote recovery of the state-endangered species, he has been using radio telemetry as a tool to better understand which areas the turtles are utilizing so they can be protected and management plans to improve their habitat can be implemented.
Additionally, radio telemetry can be used to improve Blanding’s turtle hatchling recruitment. If you’ve ever tracked any animal you understand what I mean when I say, “Easier said than done!” Finding a turtle on a mission to lay her eggs is hard enough, but trying to predict if and when she will lay her eggs seems like an impossible task. Although it’s a lot of hard work, Dr. King and I have pretty much figured it out.
After we have taken our data, the hatchlings are released back into the wetlands near their nest sites. In order to increase their chance of survival out in the wild, it has become necessary for us to assist the Blanding’s turtle population. It may take several field seasons of tracking them at Nachusa before we can get a full understanding of how they are using the area or if there are any other individuals present. For the time being, what’s important is that we are monitoring their movements, protecting critical habitat, and sparing the hatchlings the overland journey of getting to the wetlands.
Blanding’s turtle eggs are particularly vulnerable to nest predators such as raccoons, skunks, opossums, foxes, mink, and coyotes. High nest failure means low recruitment level and if juveniles are not surviving then that’s when a population begins to decline. Moreover, roads located near wetland habitat, movement corridors, and nesting areas increase risk of mortality for Blanding’s turtles.
It’s always a good idea to keep a lookout for turtles crossing the road. I know if I see a turtle in the middle of the road, given the opportunity, I will pull over and move them out of harm’s way! You never know, it could be a state-endangered Blanding’s turtle. As an undergraduate, I grew fascinated with Blanding’s turtles after seeing one for the first time on a biology field trip and I’ve always wanted to find a way to help them. Little did I know I would get to do just that!
Dr. Richard King's ongoing research on Nachusa's Blanding’s turtle management strategies is supported with a Scientific Research Grant from the Friends of Nachusa Grasslands.
If you would like to play a part in helping the turtles at Nachusa Grasslands, consider joining our Saturday Workdays or giving a donation to the Friends of Nachusa Grasslands. Donations to Friends can be designated to Scientific Research Grants.
Ephemeral ponds are temporary ponds of springtime, sometimes called vernal pools.
Springtime, melting snow, and spring rains bring water and life to the ephemeral ponds and vernal pools at Nachusa Grasslands. Amphibians and macro invertebrates use these ponds as a nursery for their young. These small bodies of water flourish in the spring and then quietly, without notice, disappear into the heat of the summer. While they exist, they offer special advantages and challenges for the life that inhabits them.
Plants and animals in ephemeral pools must be adapted to wet conditions in spring and dry conditions by early summer. Plants that thrive in vernal ponds are very often the same plants that one would find on the edge of permanent ponds. Permanent ponds overflow their banks in spring and a shoreline of sedges, grasses, and forbs begin to emerge in the cold water. These same types of plants emerge in the cold water of vernal pools. These plants will continue to thrive on the shores of a permanent pond as the water recedes and in vernal pools as the water fades and the pond dries.
Frogs and salamanders seek out ephemeral ponds as safe breeding pools and nurseries for their young. A pond that dries out part of the year, or freezes entirely, prevents fish from establishing. Fish would eat amphibian eggs, small tadpoles, or small sallywogs*; they would also compete for the macro invertebrates that provide a rich source of food for the adult and juvenile amphibians. The trade-off is the young must grow fast enough to leave the pool before it dries in the summer heat.
Nachusa’s ephemeral ponds have the advantage of being surrounded by a rich and diverse grassland. As the ponds dry, the young that managed to mature enough to leave the watery place of their youth, can venture forward into a land of plenty. Appetite-satisfying insects are plentiful. The tall grasses and abundant flowering plants provide camouflage and shelter. This is a sharp contrast to ponds among row crops, where the plants are a monoculture and are frequently sprayed with pesticide. Or, in the suburbs, where lawns are mowed right up to the waters edge, leaving no place to hide; tasty insects are sparse. Many times ephemeral ponds are filled, drained, or dug deeper to create a permanent pond, ruining the qualities that support unique macro-invertebrate and amphibian life. At Nachusa the challenges of survival in the natural world exist for amphibians, but without many of the artificial challenges that the modern world brings.
Nachusa has many of these wonderful ephemeral ponds. They can often be located this time of year by the sounds of calling frogs. Western chorus frogs and spring peepers are the first to begin calling in late March or early April and are later joined by northern leopard frogs and American toads. Readers of the blog are likely familiar with the sound of the western chorus frog, often described as the sound of a fingernail being dragged across the teeth of a plastic comb; or its contemporary the spring peeper whose call begins with peep, peep, peep. The trill of the American toad is long and carries in the night air. The northern leopard frog with its low rumble, is followed by a bit of chuckle. The copes gray treefrog begins calling around early May; its call is a similar trill to the American toad, but instead of a long steady call, the copes trill comes in quick, short bursts often two or three at a time. Listen for calling frogs after the sun sets, when the winds are calm.
One resident of Nachusa is never heard and seldom seen. The silent, but intriguing tiger salamander with its marbled skin, likely visits these ponds as a refuge and breeding site. Presently the pond waters are filled with eggs of frogs and salamanders. Soon these vernal pools will be filled with tadpoles and sallywogs* competing to be the next generation of amphibian life at Nachusa.
As volunteers and staff at Nachusa restore the native landscape, ephemeral-pond-dependent species grow in population and diversity. Drain tiles throughout the preserve have been broken or removed, and low spots have been enhanced to return the natural hydrology to the land and allow spring wet areas to return; this increases the areas for amphibian populations to expand. It has been reported that the call of the plains leopard frog has recently been heard near the Tellabs ponds. If confirmed, another species can be added to the list of animals that call Nachusa home. The ephemeral ponds surrounded by plentiful grasslands preserves the ecological diversity that is the living tapestry of Nachusa Grasslands.
Text and Photos by Paul Swanson
*Sallywogs used to denote salamander larvae vs. frog larvae.
I am a nature photographer, a freelance graphic designer, and steward at Nachusa's Thelma Carpenter Prairie. I have taken photos for Nachusa since 2012.
I have been a high school French teacher, registered piano technician, and librarian. In retirement I am a volunteer historian at Lee County Historical and Genealogical Society.