Types of Turtles
Visitors to local ponds, rivers or coast lines often cross paths with one or more of the local turtle population. Due primarily to their popularity as pets, the Red-eared Slider in the video greets many pond visitors because pet owners have historically released them into local ponds. Their aggressive nature often translates into their pushing out local turtle species from their territory.
The Tortoise and Freshwater Turtle Specialist Group at the IUCN recently published a revised taxonomy of the world's 454 turtle species (317 species and 137 subspecies).
North American turtles cover six of the families and fifty-five separate species. Species diversity reaches its highest in the Southeast. Most species inhabit freshwater environments and fit into four of the families.
Depending on the area, native turtle or tortoise species confronts challenges due in large part to habitat loss and or water degredation. This review provides background on some of the general challenges faced by native turtles and tortoises.
All twelve species of Map Turtles, for example, were recently listed in CITES Appendix III, meaning cross border trade in these species requires a permit. Two snapping turtle species (family Chelydridae) swim North American waters,the Common snapping turtle (Chelydra serpentina) and the Alligator snapping turtle (Macrochelys temminckii). It's also listed on CITES Appendix III.
Western Pond Turtle
Members of the family Emydidae, the native water turtles, inhabit freshwater environment across North America. The Western Pond Turtle (Clemmys marmorata), a western species, is listed as endangered in Washington State, with habitat loss cited as a causal factor.
The yellow-bellied slider (Trachemys scripta scripta), inhabits slow moving water bodies like ponds and lakes of the South.
The Peninsula Cooter (Pseudemys peninsularis), also known as the Florida River Cooter, lives in slow flowing rivers and streams from Virginia, south through Florida.
They are an above averaged sized turtle, growing up to sixteen inches in length. Their diet consists primarily of local plant life. The picture shows a specimen with a colorful green and yellow patterned shell.
Seven different Diamondback Terrapin subspecies (Malaclemys terrapin) represent the Emydidae family, although they present a variation on the Emydidae freshwater preference theme by inhabiting transition zones between the freshwater rivers and salt water oceans of the East Coast and Gulf of Mexico.
Although none of the subspecies grows larger than a foot in length, their shell appearance differs from location to location. Additionally, all of the subspecies share the physical characteristic of having a white face with dark markings.
North America hosts two native box turtle species.
Four subspecies of the Eastern Box Turtle (Terrapene carolina) inhabit the forest floors, swamps and grassy areas of the Eastern United States:
- Eastern Box Turtles (Terrapene carolina carolina) exhibits the widest range, extending from Southern New England, south to the Florida state line and west into Indiana, southern Illinois, Kentucky and Tennessee.
- The Three-Toed Box Turtles (Terrapene carolina triunguis) ranges through the South Central United States.
- The range of the Florida Box Turtle (Terrapene carolina bauri) is limited to the peninsula area.
Two subspecies of the Western Box Turtle (Terrapene ornata), also known as the Ornate Box turtle, inhabit dry and sandy habitats in their range.
The more common subspecies, the Ornate Box Turtle (Terrapene ornata ornata), inhabits the grasslands of the central United States from South Dakota, south through Texas. The Desert Box Turtle inhabits the grassland areas of the Desert Southwest regions, south to northern Mexico.
Four native tortoise species walk the North American soils. The least known and largest species, the Bolson tortoise (Gopherus flavomarginatus) inhabits high altitude areas of the a Chihuahuan desert in northern Mexico and areas of New Mexico and Arizona.
Listed as endangered, efforts to protect its critical habitat have been established.
The Texas Tortoise (Gopherus berlandieri), pictured above, the smallest of the four native tortoise species, inhabits areas of northern Mexico and Southern Texas. Population declines led to its being designated a protected species in 1977.
The Gopher Tortoise (Gopherus polyphemus) inhabits sandy soil areas in the Southeastern United States from Florida to the eastern parts of Louisiana. They live year round in large burrows, often measuring thirty feet in length. During the day they emerge to bask in the sun and forage for food, mostly plant life.
The western population population are federally listed as threatened, with habitat loss cited as the cause of declining populations. Florida also lists them as threatened. Georgia designated them the official state reptile in 1989.
The Desert Tortoise (Gopherus agassizii), a Southwest native species with distinct populations in the Mohave and Sonoran deserts. The Sonoran desert population tends to live along rocky hillsides, the Mohave desert population tends to live in flatland areas.
The Mojave population has been listed as threatened. In October 2008 a couple of groups petitioned to have the Sonoran Desert population likewise listed, claiming that population levels have fallen by about 50% during the past twenty years.
© 2007-2014 Patricia A. Michaels