Northern Map Turtle

Graptemys geographica

Article and photos by Linda Hagan, Maryland Master Naturalist Intern

The Northern Map Turtle is an aquatic, fresh water turtle that inhabits large rivers, streams and lakes.  They spend much of their time underwater although they do require abundant basking sites, but they are shy and will dive for safety at any disturbance. Map turtles usually forage for food in the morning and late afternoon and prefer to bask at midday. 

Northern Map turtles get their name from their appearance.  The carapace (top shell) has a shallow but definite midline keel.  It is olive colored and has designs that resemble a map, some say the lines look like waterways or topographic lines on a map.  The lines are yellow to orange in color with darker colors in between them in greens and browns.  Any pattern may be obscured by dark pigmentation in females or algae growth on the carapace. The skin is olive to brown black with thicker yellow to greenish yellow stripes on the skin of their face and limbs.  The skin design can be more noticeable due to the fact the shell can fade with age. The plastron (bottom shell) is pale yellow in adults but juveniles have a black pigment along the scute (plate) line. The Northern Map Turtles also have a large jaw surface which give the appearance of light colored lips. 

Map turtles assemble in groups to hibernate and spend their winters in deep, riverine pools where the water is cold and has a high level of oxygen.   There they will lie motionless on the bottom fully exposed.  They are able to breathe underwater because they take up oxygen through permeable skin that is well supplied with blood.

Male Map Turtles have narrower heads, oval-shaped carapace and longer, thicker tails than the females do.  The females are larger than the males with a carapace measuring up to 10.5” compared to the males with a 6.2” carapace. 

Breeding takes place in both spring and fall.  Nests are usually built on open, sandy  beaches or sand bars rather than wooded areas.  The egg laying process can take many hours, beginning at nightfall and lasting until early morning.  The female will lay 10-13 eggs per clutch and usually lays two clutches a year.  Map turtles have temperature dependent sex determination.  Warmer temperatures produce females and cooler temperatures males.  Males reach sexual maturity at around 4-6 yrs of age but females can take more than 10 yrs to mature.  The predators of their nest sites are raccoons, skunks, foxes, and river otters.  Gulls, crows, grackles and red-winged blackbirds will eat hatchlings. Adult turtles can also be prey to skunks, raccoons, coyotes and opossum. 

Map Turtles feed on a variety of food sources.  Algae, vascular plants, dead fish, snails, clams, crayfish and a wide variety of insects. 

Where many turtles such as the Eastern Box Turtle can live 75 yrs or more, the Map Turtle usually lives from 20-25 years of age.  There are 13 species of Map Turtles.  The Map Turtle we have living at FountainRock is a Mississippi Map Turtle named “Kohni” who came to live with us in 2014 on a rainy spring day.  When counting Kohni’s scutes at the time of her arrival it was estimated she was around 15 years of age.  Come visit beautiful Kohni and see why she is called a Map Turtle. 

The Northern Map Turtle has been listed as endangered in Maryland because of its restricted range.  Threats such as water pollution, waterfront development, vehicle traffic, boat propellers, habitat destruction, siltation, dams, and collection for the pet trade are all causes of the endangered status the Northern Map Turtle faces.  It is up to humans in the private and public sectors to join together to protect and restore habitat if we want to see these beautiful turtles continue to be part of our diverse ecosystems.

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Eastern Musk Turtle

Sternotherus odoratus

Article and photos by Linda Hagan, Maryland Master Naturalist Intern

The next turtle ambassador at Fountain Rock is “Axe” the Eastern Musk Turtle who was donated to the park in 2009 and has grown quite a lot since that time although he still appears small.  Axe goes on field trips with Nature in Classroom to visit a local elementary school each year.  Because he is small he is easy for presenters to handle and show the different carapaces (top shell) between other turtles such as, Toby the Box Turtle and Franklin the Wood Turtle. Each turtle has its own beauty, character, shell shape and patterns.  What child doesn’t love looking at turtles? 

The Eastern Musk Turtle also known as “Stinkpot” because of the pungent, unpleasant odor it can release as a form of protection from predators.  This odor also plays a role in courtship so they can identify possible mates.  The fluid, or secretions are yellowish in color and are emitted from four glands along the edges of its shell.  The carapace (top shell) is a arched dome which is elongated and smooth.  It is often found with algae growing on the carapace which makes it hard to see the irregular pattern of black streaks or spots.  It varies in color from gray brown to black.  The Eastern Musk Turtle has a much smaller plastron (bottom shell) than the Eastern Mud Turtle who is similar in appearance and shape.  Until you compare the two it can be hard to tell them apart.  The plastron also has a nonfunctional hinge and brown to yellowish scutes (the individual scales).

This turtle is small in size with its carapace measuring only 2”-4 1/2” in size. The males are slightly larger than the females with a longer and thicker tail with a nail on the tip of it.  The Musk Turtle has a long neck so if handling you should hold it to the rear of the carapace. The head has two yellow to white stripes on each side of its head which start at the snout and extend to the back.  One stripe is above and the other stripe is below its eyes.  The head also has  paired barbels (a fleshy filament) growing on its chin and throat. 

Although the Eastern Musk Turtle prefers aquatic habitats with slow moving water with soft bottoms, they are poor swimmers.  They spend much of their time walking along the bottom in search of food.  They are however good climbers and can be found on occasions basking on logs, but for the most part they remain on the bottom of their freshwater homes of ponds, lakes and wetlands.  They are more active at night during the warm months of the year. 

These turtles will hibernate underwater or near the water for the winter months. They will come out from hibernation by April and will mate during the active period which last until November.  Males are thought to become sexually mature at about 4 yrs of age, but the females can take up to 10 yrs to mature. When ready to lay her eggs the female will  make a shallow nest under rotting vegetation or fallen logs and nest closely to other turtles.  She will lay 2-4 eggs.  The hatchlings are our smallest North American turtles being about the size of a penny.

The Eastern Musk Turtle eats a variety of foods which include:  small snails, clams, aquatic insects like the nymphs of dragonflies and damselflies and terrestrial insects that fall in the water, worms, crayfish and small tadpoles, aquatic vegetation and carrion. 

Habitat destruction and pollution are the major threats to the Eastern Musk Turtles as it is with all turtles. 

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Eastern Box Turtle

Terrapins carolina

Article and photos by Linda Hagan, Maryland Master Naturalist Intern

I think just about every one of us has come across a Eastern Box Turtle at some point in our lives.  Maybe as a child your mom, dad, or grandparents introduced you to your first turtle out in the wild, and more than likely it was our Eastern Box Turtle.  And what vegetable gardener has not waited in great anticipation for that first ripe, juicy tomato of the season only to go into the garden and find a big bite out of it.  You look down under the tomato plant and find a box turtle with bits of your tomato hanging out of its mouth and juice dripping down it’s neck. How many good samaritans have stopped their cars when they see a box turtle crossing a road and help it get to the other side safely. 

Yes our Eastern Box Turtle is pretty recognizable.  We know the pretty brown to black carapace (top shell) with the yellow and orange, irregular blotched pattern.  It makes a  great camouflage in the forest litter because it mimics dappled sunlight.   According to researchers mature turtles can be identified by the pattern of their shells. We go to pick it up and the turtle pulls its head, legs and tail inside the hinged plastron (bottom shell) and closes it shut tight as a box.  This and the domed shape of the carapace is a perfect defense against predators.

 I for many years kept finding the same box turtle around my property, but the only reason I knew it was the same turtle was because at some point in its life someone had carved their initials into its shell. That is not a good thing to do as it can harm or damage the turtles shell, but turtles with initials and dates have turned up that show the turtle to be more than a century old. Although that type of record may be hard to prove, there is good evidence to show box turtles can live to be 80 years old in captivity.  In the wild however that is shortened to 30-40 years.  Still pretty good for a wild creature. 

The Eastern Box Turtle is a small turtle averaging 4 1/2” to 6” in length, but have been found as large as 8”.  They live in mixed or deciduous forests, farm fields, our backyards and meadows.  They prefer thick vegetation and areas with fallen and rotted trees where they can find shade to keep cool.  Although box turtles cannot swim, they will seek a stream, puddle or under a rotted log where they can sit and cool off when it becomes too hot. Overheating can kill a turtle and interfere with body functions such as a “righting reflex” that allows them to right themselves if they have for some reason been turned on their backs.

Eastern Box Turtles are hibernating by November and may return to the same hibernating spot year after year.   As soon as they emerge from hibernating in April they will eat and start searching for a mate.  Mating can take place anytime when they are active into the fall and nesting occurs usually in June.  The clutch size on average is five eggs.  Box turtles do not reach sexual maturity until 8-10 years of age.  Female turtles do not have to mate every year and can actually store sperm up to 4 years.   When the female turtle is ready to lay her eggs she may travel from a few feet to more than a mile in her home range.  The box turtle has a limited home range.  They spend their whole lives in an area from .05 to 10 acres, but usually less than 2 acres.  This is the reason if you find a box turtle crossing a road you should NEVER take it to a different area.  Simply pick the turtle up and take it in the direction it was going and release it.  Also many turtles found crossing roads in June or July are often pregnant females looking for a nesting site.  Many a well meaning human, including myself have thought they were doing the right thing by taking the turtle to what we thought was a safer area.  This is indeed detrimental to the turtle. It knows its’ home range and needs to remain there. 

There are two ways to determine whether the Eastern Box Turtle is a male or female which is easy and fun to teach children.  When I helped at “Nature in the Classroom” in a local elementary school in Frederick, I got the biggest kick out of children’s reaction when we told them to check the eyes. If the eyes are red it’s usually a male, and the plastron is concave.  Females have brown eyes and a flat plastron. 

Eastern Box Turtles are omnivorous and eat many different foods such as: earthworms, slugs, snails, insects, frogs, toads, small snakes, grass, fruits and berries, fungi, carrion and yes a few of our garden tomatoes.  But remember all those slugs and snails are munching on your flowers and vegetables too, so loosing a few tomatoes is well worth the price to pay these mild mannered turtles for getting rid of those garden pests.  Turtle eggs in turn become food for other animals.  Skunks, foxes, raccoons, snakes and crows eat the eggs, and the hatchlings become prey as well. It is all part of nature keeping its ecosystem in balance. 

Although once quite common the Eastern Box Turtle is on the decline in many states due to the loss of habitat.  The best way to protect these turtles is preserving their habitat, never disturbing their nest, and never removing them from the wild.  Remember if you see them crossing a road the best thing to do is help them cross, but do not remove them from their home range unless there is construction going on that threatens to destroy their home. At that time you should call someone from DNR and seek their advice. 

If you find a injured turtle call a wildlife expert or someone from DNR and let them know where the turtle is so they can access the injuries and they will take it to a veterinarian if needed.  If it is determined it can no longer survive in the wild because of its injuries it may go to live in a place such as a nature center where it will live out its life and become a animal ambassador to educate the public.  We have a Eastern Box Turtle named Toby as well as other turtles and animals at Fountain Rock Park. Toby came to live at Fountain Rock over 20 years ago when his injuries made it difficult for him to survive any longer in the wild.  Toby has become one of our most loved ambassadors teaching children and adults a like, at the center and in the classrooms he is taken to.  The more we learn and share with each other about the creatures we share our planet with, the more we want to protect and conserve them.

There are many do’s and don’ts involving nature we as humans have to learn. The more informed we become, the more we share that information with others, the better chance the creatures around us have of being here for future generations.  What a sad world it would be without the wonderful diversity of life. 

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