The Turtles of Nebraska, Part 2

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By Alan J. Bartels

Part One of this series discussed the uniqueness of these wonderful creatures and featured species accounts of the Western Painted Turtle, Ornate Box Turtle and Common Snapping Turtle. Part Two below continues the species accounts.

Spiny Softshell Turtle and Smooth Softshell Turtle Perhaps the most bizarre of Nebraska’s turtles are the softshells. Nebraska has two species, the spiny softshell turtle (Apalone spinifera) and the smooth softshell turtle (Apalone mutica). The spiny softshells usually have pointed or rounded projections on the front edge of the carapace. The smooth does not have these projections. This is not a foolproof method of identification since large spiny softshell turtles sometimes have reduced or almost nonexistent projections that are reduced with age. The best method of identification for the casual observer is that all spiny softshells have a horizontal ridge in the snorkel-like nostrils, and the smooth softshell turtles never have this.

When trying to positively identify the species you have just found at the end of your fishing line, stay clear of the head and sharp claws. These turtles can strike quickly and repeatedly when removed from the water. The head and neck are very long, and the turtle can reach back over its shell and bite the unknowing captor. When fishing turtle-inhabited waters, exchanging nickel-plated hooks for carbon-steel ones is a must. It is nearly impossible to remove a hook from the throat of a turtle without seriously injuring the animal. Attempting to do so also puts the captor at risk. The digestive juices of turtles will eventually dissolve a carbon-steel hook. The line should be cut as closely as safely possibly to the hook and the turtle released. I once caught a softshell turtle near Grand Island that had a treble hook from a previous angler squarely embedded in its throat. It was still actively feeding.

These turtles are sometimes called “pancake” turtles or “leatherbacks” because of their low profile and flexible shell. The leathery shell actually covers a hard shell of bone underneath. Their front limbs are heavily webbed and propel them at a fast rate through the water. They can stay under for extended periods without coming to the surface for air. Many turtle species absorb oxygen from the water through blood vessels close to the skin, but the softshells take this survival skill to a new level—they can absorb oxygen through their cloaca.

The softshells suffer the same fate as snappers, as they are sometimes killed mistakenly for being a threat to fisheries. This turtle’s narrow head and neck prevent it from taking large prey. Its diet consists mainly of insects. Mollusks and amphibians are also on the menu. It rarely consumes vegetable matter. The softshells, like all of Nebraska’s turtles, contribute to the overall health of their environment by taking advantage of diseased animals as well as dead and decaying animals when available.

Females regularly grow twice the size of the males or even larger. Both species lay 15 to 23 spherical eggs normally, but 32 eggs have been recorded for the spiny softshell turtle and 33 for the smooth. Like all turtles they see movement very well. Softshell turtles can outrun a person on level ground for a short distance. They sometimes bask together by the hundreds on sandbars, their many eyes providing great protection against approaching predators. The slightest movement often sends them scurrying to the water.

These aquatic turtles seem to prefer the moving water of rivers and creeks but are also found in backwaters sloughs and ponds and lakes near moving water.

When threatened, they can in an instant bury themselves in a sandy river bottom and then move underneath to a different location. A fisherman at a bait shop once told me, “I caught one of those out in the river. It scared me so bad that I cut the line and went home.” Sure, they are strange looking, but they are fascinating creatures and nothing to be afraid of.

False Map Turtle A far less known species in Nebraska is the false map turtle (Graptemys pseudeogeographica). It is found mainly in the Missouri and Lower Platte River systems. Recently I have observed them in the Niobrara River several miles upstream of its confluence with the Missouri River and also in Ponca Creek and the Niobrara River near Spencer, Neb.

At first glance it slightly resembles a painted turtle. Upon closer inspection a prominent ridge is evident down the center of the carapace, a serrated edge at the rear of the carapace, and it lacks the red coloration associated with Chrysemys picta complex. Females grow much larger than the males, so much so that years ago, map turtle males and females were once classified as different species. The males have longer fore claws and longer tails than females. Clutch size is usually about 10 eggs, and sometimes a female may produce more than one clutch per year.

This is one of Nebraska’s protected species of turtle. Possession of this is illegal without a scientific or educational permit from the Nebraska Game and Parks Commission. There are many subspecies of map turtles in the U.S., and most if not all are suffering population declines due to pollution, damming and channelization of rivers, collection for the pet trade and habitat destruction.

Yellow Mud Turtle The yellow mud turtle (Kinosternon flavescens flavescens) is a shy, diminutive creature. It has a strange distribution in Nebraska. It lives in the Republican River drainage in the southern portion of the state, and for some unknown reason it occurs a great distance away in several counties in the Sandhills. George Hudson’s 1940s book “The Amphibians and Reptiles of Nebraska” says, “It appears probable that this species has been introduced into Cherry County since all other records for the state are from the Republican River drainage.” However, since that time it has been recorded from several other counties in the Nebraska Sandhills, and it has likely been there for some time.

It rarely exceeds a carapace length of over 5 inches. Males are larger than females and have a longer, thicker tail with a claw at the tip. The female has a very short tail in comparison. Like the box turtle, the yellow mud turtle also has a hinged plastron that provides some protection from predators, although it cannot close it as tightly.

When captured, these turtles often give off an unpleasant odor that, in addition to the musk turtles of the southern U.S., has earned this species the nickname of “stinkpot.”

Whisker-like barbels are present on the chin. These appendages are sensory organs that detect the vibration of predator or prey, which comes in handy since visual acuity is reduced in their muddy, aquatic habitat. Insects and insect larvae, carrion and amphibians make up the bulk of its diet with very little vegetation being consumed.

These small turtles are not conspicuous usually except that they may appear in large numbers on roads following rains. Some years they are active only long enough to mate and lay eggs before going dormant again. A Nebraska zoo once had a pair of these turtles and thought they had been stolen or escaped. But after an absence of over a year, they reappeared. They had simply been underground for that time and emerged again when conditions were right. The zookeeper had been fooled several times over the years by these reclusive animals, which have been known to remain underground for two years at a time. Although this species occurs in many states, it is only the female yellow mud turtles of Nebraska that are known to sometimes bury themselves in the ground along with their eggs.

Red-Eared Slider The red-eared slider (Trachemys scripta elegans) is a survivor. Hunted to near extinction in the southeast United States, a law passed in the early 1970s making it illegal to sell turtles less than 4 inches long all but stopped the collection of the species from the wild. It has made a tremendous comeback.

As a result of commercial turtle farms, this species is now sold around planet Earth for the food and pet trade. Individual turtle farms in the United State produce in excess of one million hatchlings annually. For children and most people, pet turtles soon lose their novelty—especially after having gone through the chore of cleaning their tanks repeatedly and often. These turtles are often released. Others escape. This hardy, adaptive species has now established itself, by way of the hand of man, in Germany and Japan. In Taiwan, these turtles are released as part of religious ceremonies and are now breeding there.

Why would turtles be imported to Taiwan only to be released later? Because many of Asia’s turtle species have already been trapped and eaten to extinction. Others hover precariously close to the brink. It is a lesson those of us in the U.S. should take note of. In France, red-eared sliders outcompete that country’s only species of freshwater turtle for food and prime nesting spots. The French turtle is becoming rare as a result.

In Nebraska, this omnivore’s known native range is the southeast part of the state in the Missouri River and the Lower Platte. Lazy pet owners have created a breeding population in Lincoln, Neb. ponds as well as in a few sandpit lakes near Columbus. And it likely exists in other metropolitan areas of conterminous Nebraska. Though similar in shape to the painted turtles, the red-eared slider grows much larger. As its common name implies, it typically has a red stripe behind its eye. The stripe is rarely yellow or orange, and the length of the carapace can approach 12 inches. Sexual dimorphism is similar but even more pronounced than in painted turtles. This species and many close relatives occupy the southeast United States. In warmer climates, these turtles may lay eggs three or more times each year (five has been recorded). In Nebraska, one clutch is the norm.

The Blanding’s turtle (Emydoidea blandingii) is rare throughout most of its range but still common in parts of Minnesota and Nebraska. (Alan Bartels)Blanding’s Turtle This species largely influenced my desire to educate people about turtles. I found my first Blanding’s turtle (Emydoidea blandingii) near the Elkhorn River when I was a child. These beautiful turtles with their black and yellow smiley face became my favorite chelonian. I moved away, finished school and joined the military. When I returned to that secluded spot on the Elkhorn years later, I found my secret swamp drained and the beloved turtles gone. I began researching the species and found that similar habitat destruction was driving it to extinction across the nation.

Fossil evidence indicates that Blanding’s turtles likely evolved in what is now Nebraska and then spread south, north and east. Our neighboring states of Iowa, South Dakota and Missouri have populations of Blanding’s turtles. Minnesota’s numbers of Blanding’s turtles are second only to Nebraska. They also exist in smaller, usually fragmented populations east to Illinois, New York and Maine, as well as even Nova Scotia, Canada. While Blanding’s turtle populations in central and eastern Nebraska are small and fragmented in places due to habitat conversion, the species’ stronghold in the state and the planet exists in locations in the Sandhills because most of the natural marshes and wetlands have not been drained as they have been in other areas. The fact that they evolved here and still thrive in parts of the state is something for residents to be proud of.

The common names of most of our turtles can be deduced by looking at the turtle—mud turtles live in muddy areas (sometimes, but so do other turtles!), painted turtles have those gorgeous colors, softshells have soft shells, and snappers snap (so do others), but what is a Blanding? Actually, the common name for this turtle is shared with the last name of the man credited for first describing it to science. William Blanding was a Pennsylvania physician and naturalist. Although he gets the credit, the species was of course known to the Native Americans throughout its range; its bones and shell fragments having been found in the remains of their early camps. In some areas of the state the Blanding’s turtle is misidentified as a mud turtle.

These turtles are extremely long lived. One Blanding’s turtle captured as an adult and well cared for lived for another 77 years! It is likely that century-old examples of this species inhabit the rivers and marshes of Nebraska. Research has shown that these turtles routinely hibernate in the same places year after year. Many of these turtles then migrate to a specific pond to feed and mate—the same one annually—then lay their eggs in the same place as in previous years. Considering that some of these turtles predate our road system—and considering that they migrate to the same places each year—its no wonder why these and other species of turtle experience such high mortality on our roadways. Essentially, we built roads through their migration routes.

Recent installation of fencing that directs turtles to culverts that funnel them safely under roads have been very successful in reducing turtle mortality on some stretches of highway in the Sandhills. Though seen as an expensive waste of money by some, should scores of century-old animals be needlessly decimated as we hurry to and fro in our gas-guzzling, polluting conveyances? I think not, and I believe its money well spent. Any animal spared is one more that can perpetuate the species for future generations, and a world without turtles would be a lonely place indeed. The cost to prevent a species from becoming endangered is far less that the cost of trying to bring one back from the brink.

Blanding’s turtles are omnivores but eat mostly insects. Beetles are a staple, and crayfish, amphibians and carrion are consumed when available. This is the only Nebraska species with a bright yellow throat. The carapace is usually black (rarely brown) with yellow dots or bars. The plastron can be mostly black or mostly yellow, but most individuals will be yellow with thumb-shaped black bars along the margin. Males grow to be slightly larger than females. As many as 22 eggs have been recorded for a single clutch.

These solar-powered beasts are said to be very cold tolerant. They can creep out of an icy marsh and into a sunny spot and elevate their body temperature at least 40 degrees warmer than the air temp. Like all turtles they are cold blooded and need the energy from the sun (or a warm asphalt road, unfortunately) in order to gain the energy for daily living. Lack of these conditions forces them underwater during winter, where they slow down their bodily functions and patiently exist until spring. Blanding’s turtles have been observed swimming under the ice, and radio-tagged animals have revealed that they can move about frequently under the frozen surface of a pond without having to take a breath. Occasionally they have been known to survive the winter under logs or underground.

Though they will hiss and even urinate when startled, these turtles rarely bite when encountered. I was fortunate enough to do some volunteer work with this species under the guidance of Dr. Jeff Lang at a wildlife refuge in the Sandhills. Over 1,500 of these animals were captured and marked in two years of field work. Never did one attempt to bite me. We encountered some that had one or two limbs missing after presumably losing them to predators. Others appeared to have survived prairie fires and were horribly scarred. One I recall had a front right limb and flesh up to its elbow missing; a clean and complete white bone remained. Others had survived encounters with automobiles and kept plodding along. These beautiful animals, these Nebraska originals, are survivors.

And they all are. After persisting for so many millions of years, should any species of turtle perish at the hand of a creature as relatively recent as man? We’ve altered their world more in the last 100 years than Nature has in the last 10,000. We’ve lost many species of turtle on this planet in recent decades, and many more teeter on the brink. Will Nebraska serve as a model of conservation for the rest of the planet? In many ways we already have. But in others we are among the worst offenders.

Education is the key. I know people will protect what they appreciate, what they know about. I hope you’ve learned something from this article. And now, since you now know something about our turtles—what will you do?

 

Comments

Submitted by Anonymous (not verified) on

I have photographic evidence of false map turtles in the Lincoln area. Email me if you would like the pictures.

Submitted by Abby (not verified) on

this is a beautiful website. I love turtles. I have three, a redfoot tortoise and two RES. They are like my children, such huge personalities. Turtle conservation is something I highly prioritize. If I was ever president, I would put that top of my list. But then, I would probably never be elected in the first place.

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