Map Turtle

Genus Graptemys

Reptile

Transcript:

Today on Animal Fact Files we’re discussing map turtles. These reptiles get their common name from the intricate markings on their shells. They look like a topographic map! Fascinatingly, these patterns fade as the turtles age, and some individuals end up completely covered in algae which obscures their shell! Map turtles are also known as sawback turtles because some species have heavily keeled scutes giving their shell a saw-like appearance. Many species also have serrated edges to the lower portion of their shell. 

There are just over a dozen map turtle species and they live in North America from southeastern Canada to the states bordering the Gulf of Mexico in the US. Map turtles living further south have a preference for large bodies of water like rivers and lakes that have a current and lots of vegetation as well as islands and sandbars. Those living further north are less picky and can be found in slow moving swamps. They utilize deep pools for hiding and prefer to bask on surfaces that aren't touching the banks of the lake or river. They're often found in areas with muddy or sandy bottoms, but some live in gravel or limestone habitats as well. 

Map turtles are highly sexually dimorphic. Male map turtles range from three to six inches (8-15cm) in length at full size, but females double this! Like pond sliders, map turtle males use their long front claws to tickle a female's face for courtship. Their eggs are also temperature dependent. Females lay four to fourteen eggs in a nest constructed on a sandbar or the sandy banks of an island in their habitat. She'll do this a few times a year depending on her age, size, and species. The eggs can survive short bouts of flooding and take about 70 days to incubate. It takes around three to five years for males to reach reproductive age, but female map turtles need ten to twenty years before they're ready to reproduce! 

The long maturation process for female map turtles can make it difficult for them to bounce back from population declines. These turtles are impacted by habitat changes and the pet trade because they're collected from the wild and sold to prospective owners around the world. Half of the living map turtle species are listed as near threatened or worse due to these threats. Predators to map turtles include otters, foxes, raccoons, and crows who raid their nests. Their young are eaten by catfish and snapping turtles and adults may be taken by alligators! In the wild, map turtles are estimated to live to at least 20 years.

Map turtles are diurnal. They spend the day basking in sunlight, out of the water, to warm themselves up. Individuals living in the southern part of their range are known to do this year round, though the northern map turtles have a period of low activity during which they do not bask. In the morning and late afternoon, map turtles search out food in the form of insects, like dragonflies and cockroaches that have fallen into the water, crayfish, molluscs, like mussels and clams, as well as the occasional fish, sponge, bryozoan, or aquatic plant. 

It might seem like map turtles are closely related to the somewhat similar looking sliders or even mud turtles, but currently they're believed to be most closely related to diamondback terrapins! 

For more facts on map turtles, check out the links below. Give a thumbs up if you learned something new today. Thank you to our Patrons SpikeSpiegel93, Dad, and everyone else for their support of this channel! And thank you for watching Animal Fact Files!