The northern map turtle is a small to medium animal with lines across its shell that resemble the marks on a map. Males and females look somewhat different. The females grow to almost twice the size of the males.
They are most common in the southern United States. Some live in a few areas of the northeastern coast of the United States. Another small population lives in Ontario, Canada. You will most often see these animals in slow-moving, large bodies of water.
Northern map turtles are omnivorous but mostly eat meaty foods. Females have powerful jaws they use to eat mussels, clams, and crayfish. The males eat smaller foods like insects.
These turtles are skittish and swim away at the slightest hint of danger. They are diurnal and spend most of their days basking in the presence of other turtles. Like sea turtles, the environment determines the sex of these hatchling turtles. Females may lay one to three clutches per season.
Due to their skittishness, northern map turtles don’t make the best pets. Still, those with previous turtle-keeping experience may have success.
To keep a northern map turtle, you’ll need a large enclosure with plenty of water for swimming. They also need land for walking and basking, and you’ll need to provide them with the right temperatures.
Consult our complete care guide below to learn how to care for northern map turtles.
What Is A Northern Map Turtle?
Northern map turtles (Graptemys geographica), are small turtles with smooth shells.
They are part of the order Testudines which encompasses all turtles. They are in the family Emydidae, which comprises all basking, marsh, and box turtles. The family Emydidae is one of the largest living families of turtles in the world. Family Emydidae contains 52 species of turtles. They are generally small to medium in size. Most turtles from the family Emydidae are fully aquatic. Some are semi-aquatic or terrestrial.
Description
A full-size map turtle has an average carapace length of 6-11 in (15.2-28 cm). Their shells, or carapaces, are slightly domed with a strong keel down the center. Their carapaces do not have a hinge, but they do have deciduous scutes.
The carapace is a dark grayish-green color with winding, cream-colored lines. The lighter lines have a darker border that helps them to stand out. The lines resemble the markings on a map, giving the animals their names. As a turtle ages, the lines usually become darker and less noticeable.
The back edge of their carapace is flared and sharply toothed. The underside of their shell, the plastron, is pale yellow and wide. Their skin is dark green to black with contrasting yellow lines. Most individuals also have a light-colored oval spot behind each eye.
Common Names: Northern Map Turtle, common map turtle
Scientific Name: Graptemys geographica
Origin: North America
Common Map Turtle Size (Length): 6-11 in (15.2-28 cm)
Common Map Turtle Weight: Males — 150–400 g (5.3–14.1 oz), Females — 0.67–2.5 kg (1.5–5.5 lb)
Northern Map Turtle Lifespan: 18-20 years
Enclosure Size: 5-10 gallons per inch of carapace length
Temperament: Skittish
Ease of Care: Moderate
Males VS Females
Males and females display sexual dimorphism. Sexual dimorphism means males and females have differing characteristics. A male’s carapace is more oval, and their average carapace length is 6.3 in (16 cm). Females have larger and broader carapaces with an average length of 10.7 in (27.3 cm).
Male northern map turtles have longer and thicker tails. Their vent is also posterior to the margin of their carapace. Males have longer front claws and a more distinct keel. Conversely, females have broader heads than males.
Painted Turtles VS Northern Map Turtles
Onlookers often confuse northern map turtles with painted turtles. They have many similarities that make them easily confused. Yet, painted turtles stand out because of their bright red stripes. These stripes live on their legs, the underside of their shell, and the base of their neck. Northern map turtles lack any red coloration. A painted turtle’s skin also tends to be much darker than a northern map turtle’s.
“Common” Map Turtles
Northern map turtles are also known as the “common map turtle.” Yet, scientists are now trying to avoid using the word “common” when referring to animals. They argue the word “common” leads people to believe animals are abundant. Many times, the opposite is true. The northern map turtle, for example, is facing many threats.
Common Map Turtle Range
Common map turtles are more common and widespread than any other map turtles.
The only location they live in New England is a singular lake in Vermont. You can see them swimming in Lake Champlain and across its major tributaries. They are considered of special concern in Vermont and are uncommon in the state.
These turtles also live throughout the Great Lakes regions. They live as far west as eastern Minnesota and southern Wisconsin. You will also see them living in the south. They live throughout Arkansas, Alabama, Kansas, Tennessee, northeastern Oklahoma, and northwestern Georgia.
In the United States, they do not occur further north than Vermont. Some populations also live within the Susquehanna River system of Pennsylvania and Maryland. To the east, they live in the Delaware River system.
They are common in northeastern river drainage systems leading to the Atlantic Ocean. Some populations also live in southeastern river drainage systems. These systems lead to the Gulf of Mexico. Yet, they do not live in the Mississippi River system or other nearby river systems.
You can also see these turtles in limited ranges across Canada. They only live in southern Ontario and a tiny part of southwestern Quebec.
There is a singular non-native European population living in the Czech Republic. These turtles came to the Czech Republic after they were kept as pets. They were released after their owners no longer wanted them. Still, they are not doing well and are not considered invasive.
Rather, the red-eared slider threatens the northern map turtle. They are an invasive species also from North America. The invasive red-eared sliders also threaten aquatic turtles native to the Czech Republic.
Common Map Turtle Habitat
Northern map turtles are semi-aquatic, though they spend most of their lives in the water. They only leave the water to bask and lay their eggs. They prefer larger bodies of water like lakes and rivers. Finding them in smaller water systems like creeks or ponds is rare.
Still, they prefer slow-moving water. They also like to have plenty of areas for basking, including fallen logs. They enjoy areas with lots of aquatic vegetation to hide in. You will likely see these animals in clear, healthy water with gravel substrates.
Northern Map Turtle Diet
Northern map turtles are omnivorous but primarily carnivorous. They are scavengers who always eat in the water. They mainly search for their food in the morning and evenings.
Due to their vast size difference, females and males eat different kinds of foods. Females enjoy larger prey like mussels, large snails, clams, and crayfish. Their larger heads allow them to crush the shells of their prey. Males cannot do this as easily. After crushing the shells, females get rid of the exoskeletons. Then, they swallow the leftover prey. Males stick to smaller animals like tiny snails, small crustaceans, and insects.
Both males and females feed on dead fish and the occasional plant matter. These turtles mostly eat plant matter accidentally. It gets swept up alongside their other meaty food. Yet, males seem to frequent areas of aquatic vegetation more than females and eat more.
Behavior & Temperament
During winter, northern map turtles hibernate. They usually choose an area where the water is deep, about 10-20 ft (3-6.1 m), and slow-moving.
Usually, northern map turtles hibernate in small groups of five to ten individuals. In one area of Virginia, these turtles have been spotted hibernating in groups of 100 or more.
Many turtle species bury themselves in the muddy substrate while hibernating. Northern map turtles are an exception. They remain exposed during dormancy. The turtles seek a place to hide within large root wads, submerged logs, large rocks, and crevices.
They are dormant over winter, usually between November and early April. Still, they may come out of dormancy long enough to change their resting location. During their winter resting period, they do not eat.
Some researchers have noted individuals staying active over winter. They sometimes swim beneath the surface of the ice. Remaining active over winter seems to be more common in males than females.
They are most active beginning in late spring and lasting through early fall. They are powerful swimmers with fully-webbed limbs.
Home Range
The home range of these turtles is about 1.2-14.9 miles (2-24 km). They can travel significant distances, especially during their most active seasons. Females have to find the perfect nesting site. So, they travel longer distances than their male counterparts. Still, males also spend significant time traveling. They like varying their summer and winter locations.
Basking
Northern map turtles spend much of their time basking on fallen logs and rocks. Individuals will spend upwards of eight hours per day basking in the sun. They are social animals who bask together in large groups of 10 or more. They are even known to share their basking sites with other species of turtles.
Basking is essential to the health of these turtles because they are cold-blooded. They cannot regulate their body temperature independently. They rely on the heat from the sun. Basking helps raise their core body temperature. It also reduces the amount of algae that grows on their shells.
The sun also prevents the turtles from the plague of external parasites like leeches. Further, the sun boosts their immune system by allowing their skin to produce vitamin D3. Vitamin D3 is necessary for the health of their bones and shells. It also aids in digestion for better gut health.
These turtles are very skittish. They will swim away at the slightest sign of danger.
Juveniles and young adult map turtles usually bask away from the adults. They may rest upon smaller logs, rocks, and algae mats.
Reproduction
Male northern map turtles reach sexual maturity much faster than their female counterparts. Males become sexually mature at about four to six years of age. Females take longer, only becoming sexually mature at about 10 to 14. Both male and female turtles are sexually mature when their carapace length is at least 7.5 in (19 cm).
Mating
Northern map turtles typically mate in deep water during the spring and fall. The male initiates mating by tapping the long claws of his front feet against the face of the female.
A female preparing to lay eggs will begin to bask longer than her male counterparts. The extra vitamin D3 produced from basking helps speed up egg production.
Choosing A Nesting Site
As the females become ready to lay eggs, they must choose the perfect nest site. Most females prefer sandy areas with lots of open canopies and well-draining soil. Their nesting sites are usually within a few hundred feet of their watery habitat.
Creating the nest and laying the eggs can take several hours. Using their back feet, they dig deep holes into the sand to create their nest. Then, they deposit their eggs inside. Often, this process begins as the sun goes down and doesn’t end until the early morning.
Laying The Eggs
Females begin laying eggs around late spring to early summer. The exact time they lay their eggs depends on where they live. Incubation usually occurs for 50 to 70 days before the eggs hatch in early fall.
Map turtle eggs are oval with a length of approximately 1.3-1.5 in (3.3-3.7 cm). The width of the eggs is usually about 0.7-1 in (1.8-2.5 cm). Female northern map turtles lay 8-19 eggs per clutch, with an average clutch consisting of 12 eggs. In colder regions of their range, female turtles may only lay one clutch per season. In parts of their warmer range, female turtles may lay as many as two or three clutches per season.
The mother does not stick around to protect her eggs, so they are often victims of predation. Predators of northern map turtle eggs include raccoons, skunks, river otters, and foxes.
Hatchlings
At the time of hatching, juveniles have an average carapace length of 1-1.4 in (2.5-3.5 cm). Hatchlings look very similar to their adult counterparts in color.
The sex of northern map turtles is determined by the temperature of the environment. The hatchlings will primarily be male at temperatures of about 77 °F (25°C). The hatchlings will primarily be female at about 86 °F (30°C).
After hatching, juvenile turtles immediately begin moving downstream. They are seeking out a suitable home range.
It is rare for northern map turtle hatchlings to overwinter in their nests, but they will do so about 20% of the time. Hatchlings choose to overwinter in their nesting site because they’ve hatched late. The cold temperatures make it unsafe for them to begin exploring outside the nest. Sometimes, the hatchlings will delay hatching until after winter. They choose to remain safely inside their eggs during the colder months.
Hatchlings are in just as much danger as they were as eggs. They remain small and nearly defenseless until they grow bigger. Common predators of hatchlings include red-winged blackbirds, crows, grackles, and gulls.
Adults
Even as the turtles grow into adulthood, they remain in danger from larger predators. Raccoons, skunks, opossums, and coyotes all prey upon adult northern map turtles.
Conservation
These turtles were recently assessed by the International Union for the Conservation of Nature (IUCN). They list the species as “least concern.” Still, their populations are likely declining.
Unfortunately, northern map turtles face a multitude of threats. They are sensitive to poor water quality, likely because it reduces the amount of prey in the area.
Increasing development near their habitats eliminates their basking spots and nesting sites. Losing shoreline areas in their habitats is one of the greatest threats to this species.
Females are particularly at risk. They must cover further distances by looking for suitable nesting sites. They must travel over land and are at risk of being struck by vehicles.
Such risk does not go away in the water, as swimming turtles are often struck by boats. Not only do boats hit these turtles, but they can disrupt their normal behavior. Boats produce loud sounds and disruptive wakes. These disturb the turtles’ normal basking and nesting behaviors.
Northern map turtles are often the victims of fishing by-catch.
The eggs face predation by natural predators like raccoons, skunks, and foxes. Yet, the eggs face the threat of unnatural predators as well. In some areas, humans harvest their eggs for consumption. The eggs are often stolen for use in the illegal pet trade.
Recently, American waterways have been having trouble with invasive zebra mussels. These invasive mussels are causing problems in the waterways. Still, they are also likely helping the northern map turtle populations. The zebra mussels provide a reliable source of food to the turtles. So, the turtle populations remain stable for the time being.
In fact, female northern map turtles may be the key to controlling invasive zebra mussels. Their strong jaws help reduce the populations of mussels in the areas they are abundant. The turtles are also helping to reduce the invasive populations of Asian clams.
Care
It is possible to keep northern map turtles as pets, but it’s not very common. Their uncommon status in the pet trade is likely because they are one of the more difficult species to care for. Map turtles are specialized and more evolved than other turtle species. So, they need specialized care.
Enclosure
Northern map turtles are an active species, so they need plenty of room to move around.
A single adult northern map turtle will likely need an enclosure of at least 100 gallons. An adult map turtle should have five to ten gallons of water for each inch of carapace length. Since males are smaller, they will be happier in smaller enclosures than females need. Still, these turtles love to move and are very active, so bigger is better. You can never get an enclosure that is too large for these turtles.
Most people buy their turtles as juveniles. You can start with a smaller enclosure if you do so. Remember that you’ll need to upgrade your turtle’s tank as they grow. Usually, it is easier to get a full-sized tank immediately upon purchasing your turtle. You won’t have to keep upgrading them.
The enclosure should be filled with about 4-5 in (10.2-12.7 cm) of water if you’re starting with juveniles. The shallower water will help them build their swimming skills while preventing drowning. Adults are excellent swimmers who enjoy deep water, so they should have enough space to dive.
Northern map turtles are only semi-aquatic, so you still need to provide them with some land. Most of their enclosure should be water, but they need enough land to walk around, bask, and burrow.
Outdoor Ponds
Due to their size and activity levels, northern map turtles do well in outdoor ponds. Remember that they hibernate over winter. So, you’ll need to make accommodations when the temperatures drop. You’ll need to bring your turtles inside in most areas over the winter months. Turtles should come inside once the temperatures drop below 40-50°F (4.4-10 °C).
Even so, you should aim to keep them cool once inside to allow them to mimic their natural behavior. Dropping the temperatures will lower their activity levels. It also prepares them for spring breeding if you so desire.
Secure your outside pond with a sizable fence for your turtle’s protection. The fence prevents your turtle from escaping and prevents predators from getting inside.
Basking
As active baskers, you need to provide your turtle with plenty of space for laying out and enjoying the “sun.” The most important part of the basking spot is that it’s secure and stable. You don’t want to worry about your turtle falling off its rock. You can use artificial or natural materials for your basking spot. There are plastic basking spots explicitly designed for turtles. You can also choose large pieces of driftwood or rocks.
Substrate
Many map turtle caretakers prefer not to use substrate. A tank without substrate is easier to keep clean, although it doesn’t look as nice. Substrates in your tank should be easy to clean because turtles are quite dirty. A dirty tank can leave your turtle susceptible to illness and infection.
Substrates safe for map turtles include sand, river pebbles, or crushed coral. Avoid substrates like heavy, rough stones that can cut your turtle’s skin. Scratches from the rough substrate can leave your turtle susceptible to skin infections.
Decorations
These turtles enjoy hiding and burrowing. So, caves, rocks, vegetation, and other decorations are necessary. Ensure that all decorations are securely attached to the tank. They should also be large enough for your turtle to swim through. You’ll want to prevent your turtle from getting stuck, which could result in drowning.
It’s ideal to choose live aquatic plants over fake ones. Live plants help keep the water healthy and clean, and they offer a healthy snack for your turtle. Still, artificial plants have their advantages, too. They’ll never die, and they come in various pleasing colors. Choose silk plants over hard plastic whenever possible. Silk plants are safer for your turtle as they won’t cut their skin.
Cleaning & Water Maintenance
Turtles are dirty, and the northern map turtle is no exception. You must keep their enclosure clean to prevent them from getting sick. A dirty tank leads to a boost in ammonia, nitrite, and nitrate. Chronically dirty tanks can lead to ammonia poisoning, sickness, and death.
All aquatic turtle tanks should have a powerful filter. Getting a filter double the size of what you think you need is always a good idea. If your aquarium holds 50 gallons of water, you should buy a filter equipped to handle at least 100 gallons. Doing so ensures you’ll have a filter powerful enough to handle the mess your turtle creates.
Besides the filter, you’ll need to perform routine water changes once a week to once every two weeks. Avoid removing all the water at once. You risk shocking your turtle or messing up the balance of beneficial bacteria. Instead, change about 30% of the water at a time.
It’s also essential to add water conditioner to all new water you’ll be adding to the tank. Water conditioners remove harmful chlorine and detoxify heavy metals.
Temperature & Lighting
You must include UVB heat lamps in your enclosure. They provide your turtle with the necessary levels of vitamin D3. They also help it regulate its body temperature. Without a UVB bulb, your turtle will develop metabolic bone disease (MBD). MBD is painful and can be fatal when left untreated.
Keep in mind that UVB bulbs gradually degrade and become less effective. You should replace UVB bulbs every 6-12 months for your turtle’s health.
It’s also good to have daytime bulbs, whether they emit heat or just light. Northern map turtles are diurnal and are most active during the day. Bright, daylight bulbs help replicate their natural environment. They are also essential if you’re keeping live vegetation in your tank.
Turtles living in an outdoor pond will not need supplemental lighting.
How To Use Light & Heat
Keep daytime bulbs on for about 14 hours a day during the summer and about 10 hours a day during the winter.
Ensure the heat lamp sits about 12 in (30.5 cm) from your turtle’s basking spot to prevent burns. The basking spot should be about 90-100°F (32.2-37.8 °C) at its hottest point. The ambient temperature of the rest of the enclosure should be between 75-85°F (23.9-29.4 °C). At night and over winter, it’s okay for the temperatures to drop as much as 5 degrees.
Water Heaters
You should also provide your turtle with a water heater to keep its swimming space warm. Keep the water temperature between 70-80°F (21.1-26.7 °C).
It’s best to use titanium water heaters for turtles to prevent burns when your turtle rubs against them. You must use a guard with glass heaters if you choose to use them.
Tank Mates
Northern map turtles tend to be social animals. They often do well with other turtles of the same or differing species. Still, cohabitation can be tricky in captivity because they need lots of space to move around. More active, dominant, or larger turtles may bully or intimidate more docile ones. It’s usually best to only keep one turtle at a time and avoid housing more territorial females with others.
Always provide more than enough space and hiding places when housing multiple turtles. Monitor the interactions and prepare to separate your turtles if needed.
Diet
It is pretty easy to feed northern map turtles born and raised in captivity. Usually, they readily accept pellets which are a healthy staple. Choose a turtle pellet comprising 30-40% protein and less than 20% fat. The pellets should also have a high calcium-to-phosphorous ratio. Having lots of calcium keeps their bones and shells strong.
You should also provide your northern map turtle with live foods two to three days a week. Doing so provides them with enrichment by stimulating their hunting instinct. It also adds a bit of variety to their diet.
Safe Foods
Here are 11 meaty live foods safe for your northern map turtle:
- Earthworms
- Crayfish
- Crickets
- Bloodworms
- Blackworms
- Feeder guppies
- Dubia roaches
- Freeze-dried shrimp or krill
- Silkworms
- Snails
- Mussels
Northern map turtles are primarily carnivorous but eat some leafy greens in the wild. So, you can occasionally supplement them with these 12 vegetables:
- Romaine lettuce
- Red leaf lettuce
- Green leaf lettuce
- Endives
- Kale
- Escarole
- Collard greens
- Dandelion greens
- Raw grated squash
- Raw grated sweet potato
- Carrots
- Green beans
How Often To Feed
A northern map turtle’s diet is quite different in captivity than it is in the wild. Wild northern map turtles sometimes eat vegetation. Still, most of their diet comprises meat. In captivity, you’ll provide vegetables daily. Only a fraction of their diet comprises protein. The pellets that are the staple of your pet turtle’s diet are high in protein. So, they don’t need to eat meat as often as they would in the wild.
Juveniles under six months of age need more protein than their adult counterparts. Their diet should comprise 50% protein and 50% vegetable matter. They also need feeding more often than adults. So, you should provide them with pellets and vegetables daily.
Juveniles between 6-12 months of age also need more protein than adults. Continue giving them 50% protein and 50% vegetable matter. Yet, they don’t need to eat as often as younger turtles. You can begin cutting their pellets back to once every other day. Continue providing them with fresh vegetables every day.
Adults don’t eat as often as juveniles and tend to eat more vegetables. Their diet should comprise about 25% protein and 75% vegetables. You can give them vegetables daily but only feed them protein twice a week.
How Much To Feed
Provide a dish of pellets about the size of your turtle’s head. Provide a plate of vegetables about the size of your turtle’s shell. Following these guidelines helps ensure you don’t under or overfeed your pet.
Supplements
You should also provide your turtle with calcium supplements. Give them access to a cuttlebone or calcium block at all times. You should also sprinkle a bit of calcium overtop their daily meal.
Handling
Northern map turtles are skittish and will swim away at the slightest hint of a threat. So, you should keep handling to a minimum, only when it is essential. So, these turtles are best for keepers who enjoy observing rather than handling them.
Further, buying a northern map turtle bred and raised in captivity is better. Avoiding buying a turtle who has been taken from the wild. They do not adapt well to captivity. Captive-bred turtles are likely to be more docile and are less likely to harbor parasites.
Northern Map Turtle Care, In A Nutshell
Consult this northern map turtle care sheet for quick care tips:
| Northern Map Turtle Care | |
| Enclosure Size | 5-10 gallons per inch of carapace length |
| Temperature | Daytime Temperature — 75-85°F (23.9-29.4°C) Nighttime Temperature — 5 degrees lower than daytime tempBasking Temperature — 90-100°F (32.2-37.8°C)Water Temperature — 70-80°F (21.1-26.7°C) |
| Lighting | UVA & UVB lighting 14 hours/day over summer UVA & UVB lighting 10 hours/day over winter Heat Lamp |
| Substrate | Not Necessary Safe Substrates Include: Sand River PebblesCrushed Coral |
| Decorations | Basking Platform Hollow Logs Caves Large Rocks Live/Silk Plants |
| Tank Mates | Do Best Alone |
| Diet | Juveniles: 50% Protein/50% Vegetables Adults: 25% Protein/75% Vegetables |
| Handling | Minimal to No Handling |
FAQs
Northern map turtles are skittish animals who may bite when frightened, but it’s not common. A startled northern map turtle will dive and swim away to avoid danger. They are likely to hide in their shell and release their bladder when handled if they can’t get away. Most will not bite, but if you place your finger too close to their mouth, they may give a painful bite.
The cost of map turtles varies between states and countries. Some may cost as little as $25, while others may cost as much as $1,000. Usually, the cost of the turtle itself is cheaper than the cost of the enclosure you’ll need to set up.
