Map Turtles: A Comprehensive Guide to Care and Husbandry
The map turtle (Graptemys geographica), with its intricately patterned shell, is a captivating creature. However, prospective keepers of these North American aquatic turtles should be aware that their beauty belies a demanding nature. Providing the correct habitat, maintaining impeccable water quality, and utilising appropriate technology are paramount to ensuring the health and longevity of these reptiles in captivity. Replicating their natural environment as closely as possible is the key to success.
Natural Habitat and Distribution
Map turtles are native to eastern North America, favouring large, slow-moving rivers and lakes. In Canada, they are found in the southern regions of Ontario and Quebec. Their preferred habitats are characterised by complex aquatic structures, soft shorelines, and excellent water quality. These environments offer abundant basking opportunities, clear, oxygen-rich water, and a diverse underwater landscape. When designing a home aquaterrarium, these factors must be carefully considered.
The International Union for Conservation of Nature (IUCN) Red List indicates that the map turtle is not currently classified as endangered. This means there are generally no specific legal restrictions on keeping them as pets. However, it is vital to source map turtles from reputable breeders to avoid inadvertently supporting the capture of wild specimens. While formal qualifications are not typically required to keep these turtles, a thorough understanding of their specific needs is absolutely essential for their well-being.
Identifying Characteristics
The most distinctive feature of the map turtle is its shell. The carapace, or upper shell, is typically olive-green to brown, adorned with fine yellow lines that resemble the contour lines on a map. This intricate pattern is what gives the turtle its common name. The dorsal ridge of the shell is slightly keeled, and the rear edge has a serrated appearance. The plastron, or lower shell, is usually a uniform yellowish colour, although juvenile turtles may exhibit dark lines along the seams.
The head and neck are marked with yellowish stripes, and a light-coloured spot is present behind each eye. Map turtles exhibit pronounced sexual dimorphism, meaning there are significant differences in appearance between males and females. Females can attain a shell length of up to 27 centimetres and are considerably bulkier than males. Males, on the other hand, rarely exceed 16 centimetres in shell length, possess a slimmer head shape, and have longer claws.
Behaviour and Temperament
Map turtles are known for being alert, shy, and primarily active during the day (diurnal). They are easily startled by movements outside their aquaterrarium and will often dive for cover when disturbed. They can be difficult to accustom to human presence, making them more suitable for observation than for handling. Their daily routine typically involves alternating periods of basking and swimming.
In a properly designed and stimulating environment, map turtles can be active, curious, and generally peaceful towards each other, provided they have ample space. Communal basking is a common behaviour, where several turtles will gather together under heat lamps or on basking platforms.
Housing Requirements
As highly active aquatic turtles, map turtles require a spacious and well-designed aquaterrarium. The enclosure should include both deep swimming areas and shallower zones with calm water. A large, dry basking area equipped with a UVB lamp, capable of reaching temperatures up to 35°C, is particularly important.
These turtles have significant spatial needs. For females, particularly when kept in groups, a tank with a volume of at least 600 litres is recommended. Enrichment can be provided through a thoughtfully designed environment featuring climbing roots, hiding places, and varied feeding strategies. Offering live food, such as snails or crayfish, can also stimulate their natural hunting instincts.
Essential Care and Maintenance
Maintaining stable water quality is critical for the health of map turtles. The water temperature should be kept between 22 and 26°C, and the water must be clear, well-filtered, and adequately oxygenated.
A robust filtration system, regular partial water changes, and precise temperature control are essential components of responsible map turtle care. The turtles must have access to a completely dry land area for basking, which should be equipped with a UVB lamp. In addition to light and heat, a timer-controlled lighting system is beneficial for simulating the turtles’ natural day/night cycle.
Structural elements such as stones, branches, roots, and aquatic plants serve not only as visual barriers but also contribute to territory formation and encourage movement within the aquaterrarium. Outdoor housing during the summer months is generally possible and even beneficial, provided the enclosure is secure, well-fenced, and protected from predators.
Winter Dormancy
In their natural habitat, map turtles undergo a period of winter dormancy, lasting from November to April, depending on their geographical location. During this time, they remain at the bottom of rivers or lakes, sheltering among roots, under submerged wood, or in bottom sediments. A high level of oxygen in the water is crucial, as they absorb oxygen through their skin, mucous membranes, and throat during this period, rather than surfacing to breathe.
In captivity, replicating this winter dormancy is an important aspect of their annual cycle. It helps to stabilise their metabolism, prevent obesity, support a strong immune system, and is often necessary for successful reproduction. Preparation for dormancy begins in late summer with a gradual reduction in water temperature and food intake. During winter dormancy, the optimal water temperature for map turtles is between 4 and 8°C. The tank or winter quarters must be well-ventilated to prevent oxygen deficiency.
Dietary Needs
In the wild, map turtles primarily consume animal matter. Adult females, with their powerful jaws, specialise in consuming hard-shelled prey such as mussels and snails, while males and juveniles favour smaller insect larvae and crustaceans. In an aquaterrarium, a varied, protein-rich diet that closely mimics their natural food sources is essential. This should include amphipods, aquatic insects, mussel meat, shrimp, and high-quality commercial turtle food.
Cuttlebone or calcium supplements should also be provided to prevent shell problems. Occasional supplementation with plant-based foods, such as aquatic plants or dandelion leaves, is acceptable but should not be a primary component of their diet. The quantity of food should be adjusted according to the turtle’s age: juveniles should be fed daily, while adult turtles typically need feeding only two to three times per week.
Common Health Issues
Like many turtle species, map turtles are susceptible to health problems resulting from inadequate care. Common issues include shell softening due to insufficient UVB exposure, respiratory diseases caused by low temperatures or drafts, and digestive problems stemming from an unsuitable diet. Poor water quality can also lead to skin and eye infections.
Stress caused by overcrowded tanks, lack of hiding places, or aggressive tank mates can manifest as behavioural problems. Female turtles, in particular, are prone to obesity due to lack of exercise and overfeeding, which can lead to egg-binding. A veterinary check-up at least once a year, and after any significant changes in husbandry, is recommended.
Careful health monitoring is also crucial before initiating winter dormancy, as only healthy turtles should undergo this phase. An attempted dormancy with an unhealthy turtle can lead to respiratory problems or even death. Overwintering in an outdoor pond is only feasible if the pond is frost-proof, sufficiently deep, and protected from predators. Alternatively, a cooled indoor setup or a specialised refrigerator with a large water container can be used, allowing for continuous monitoring of temperature, oxygen levels, and water quality.