Archive - March 2017

​​Turtles are reptiles that have a shell and no teeth. The shell has as many as 60 bones. It has two sections: a carapace, covering the animal's back, and a plastron, covering its belly. In most species, large scales, called scutes, cover the bones. However, in softshell turtles, a tough, leathery skin replaces the scutes. Most Illinois turtles can pull their head and neck into the shell. In species such as box turtles and mud turtles, the plastron is hinged, allowing it to close on the carapace. Turtles usually have a tail. The tail of males is longer and heavier than the tail of females.

​Kingdom: Animalia
Phylum: Chordata
Class: Reptilia (lizards, snakes and turtles) - These organisms develop from and amniotic egg, which is either deposited on land or retained within the female for the extent of its development. The egg provides everything the embryo needs to develop. The shell of a reptile egg is leathery. Fertilization is internal. Reptiles are covered in scales, and their skin is dry.
Order: Testudines (turtles) - Turtles are classified in this order. They have a bony or leathery shell.
Family Chelydridae - The snapping turtle family is composed of two species. These turtles are found only in North and South America. These turtles are aquatic.
     snapping turtle (Chelydra serpentina)
     alligator snapping turtle (Macrochelys temminckii) [state endangered]

Family Emydidae - The basking, marsh and box turtles are small to medium in size. Most of them are aquatic, but a few species are semi-aquatic or live on land.
     painted turtle (Chrysemys picta)
     spotted turtle (Clemmys guttata) [state endangered]
     Blanding’s turtle (Emydoidea blandingii) [state endangered]
     northern map turtle (Graptemys geographica)
     Ouachita map turtle (Graptemys ouachitensis)
     false map turtle (Graptemys pseudogeographica)
     river cooter (Pseudemys concinna) [state endangered]
     woodland box turtle (Terrapene carolina)
     ornate box turtle (Terrapene ornata) [state threatened]
     pond slider (Trachemys scripta)

Family Kinosternidae - The mud and musk turtles are found in North and South America. These are small, plain turtles.
     yellow mud turtle (Kinosternon flavescens) [state endangered]
     eastern mud turtle (Kinosternon subrubrum)
     eastern musk turtle (Sternotherus odoratus)

Family Trionychidae - Softshell turtles may be found in Asia, Africa and North America. These turtles are round and flat. They have a leathery shell. The feet are webbed.
     smooth softshell (Apalone mutica) [state threatened]
     spiny softshell (Apalone spinifera)

​The largest Illinois turtle is the alligator snapping turtle (Macrochelys temminckii). The biggest one ever found in our state weighed about 160 pounds. The smallest Illinois turtle is the spotted turtle (Clemmys guttata). Its greatest recorded shell length in Illinois is 4.7 inches.

​Reptiles produce young in eggs with a leathery shell. In turtles, the eggs are deposited on land in a nest, usually a hole in the ground scooped out with the female turtle's back feet. After egg-laying, the female uses her back feet to pull dirt into the hole and pack it down. When the nest is covered, most female turtles leave it immediately. The young are on their own when they hatch. Most Illinois turtles lay oval eggs, but softshells and snapping turtles lay spherical eggs. Small species, such as the spotted turtle, may lay only three to five eggs in a nest, while the larger snapping turtle (Chelydra serpentina) lays 20 to 40 eggs.

​Some turtle species live in specific habitats. For example, the eastern box turtle (Terrapene carolina) is a woodland species, and the ornate box turtle (Terrapene ornata) is a prairie species. Rivers are the favored habitat of the smooth softshell turtle (Apalone mutica), alligator snapping turtle and northern map turtle (Graptemys geographica). Blanding's turtles (Emydoidea blandingii) are commonly associated with marshes. Mud turtles visit temporary ponds or wetlands, while the eastern musk turtle (Sternotherus odoratus) resides in permanent water. The snapping turtle, painted turtle (Chrysemys picta), pond slider (Trachemys scripta) and spiny softshell (Apalone spinifera) turtle thrive in a variety of habitats and conditions.

​​Most Illinois turtles eat whatever plant or animal material is available. Even a snapping turtle's diet may include large amounts of plants along with the animal food it usually eats. Softshells are carnivores, feeding on aquatic invertebrates, such as aquatic insects. Map turtles eat snails, clams and some insects. Diets of certain species change with age. For example, young sliders are carnivores, feeding on insects. Adult pond sliders, however, mainly eat plants.

​Most turtles search for food slowly along the bottom or over weed beds, grazing on vegetation and eating slow-moving animals. A few species catch fast-moving prey by ambush. Such turtles usually are colored to blend with their environment and have long, muscular necks that can strike out at prey from a distance. A snapping turtle with its long, bumpy neck, mud-colored body and algae-covered shell, illustrates these characteristics well. The softshell turtle's pancakelike shape allows for quick hiding beneath a thin layer of the sand bottom from where it can surprise its prey.

​​Six turtle species in Illinois are state endangered and one is state threatened. Turtle population declines are due to several factors. Loss of wetlands, siltation and channelization of Illinois’ rivers have seriously affected species. A new concern is the growing demand for turtle meat and products in Asia. Food species (sliders, snappers, softshells) and pet trade species (box turtles, spotted turtles) draw high prices in that market. As Asian species disappear, markets shift to the United States to meet the demand. While a special license is needed to collect turtles in Illinois for commercial purposes, their high asking price makes poaching tempting to some people. The keys to conserving Illinois' turtles will be the rigid enforcement of current protective laws and the setting aside and maintenance of ample habitats. If these guidelines are followed, we can expect turtles to remain in our Illinois forests, prairies, wetlands and waterways for many years to come.