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| The Ringnecked Snake, Diadophis punctatus Baird & Gerard, 1853. Photographed in Douglas County, Kansas. Ringnecked Snakes range from southeastern Canada and the east coast of the USA westward to California and southward into Mexico. These small snakes may reach 700 mm, but most are much smaller. They feed on earthworms, amphibians, small snakes, and lizards. The snake in the photo is referable to the subspecies D. p. arnyi. Molecular studies suggest that populations east of the Mississippi are genetically distinct from those to the west of the river. |
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| The Mud Snake, Farancia abacura Schlegel, 1837, ranges from eastern Virginia southward to all of peninsular Florida and westward to eastern Texas and northward in the Mississippi River Valley to southern Illinois. This snake was photographed in central Florida and represents the subspecies F. a. abacura. Highly aquatic, the adult mud snake feeds primarily on amphiumas, large aquatic salamanders. But juveniles feed on other amphibians and fish. Adult maximum size is 2.07 m, but most adults are smaller. Mud snakes inhabit swamps, marshes, and other bodies of water that have dense vegetation. When captured they use their hard, spine-tipped tail tip to probe, as if to mimic biting. The result is to startle the potential predator into releasing the snake. They tend to leave the water on rainy nights and travel overland. Females lay eggs, and a clutch of 104 has been reported, usually clutches are smaller. The female may attend the eggs which are laid in a moist cavity in a stream bank, or hollow log near or in the water. |
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| Western Hognose Snake, Heterodon nasicus Baird & Girard, 1852. Whiteside County, Illinois, USA. These specimens are referable to the subspecies H. n. nasicus. The Western Hognose Snake may attain an adult length of more than a meter, but most are in the 380-630 range. It ranges from south central Canada southward to central Mexico. To the east and west of this Great Plains distribution are disjunct populations, suggesting the species has been more widespread. Most authors suggest that it feeds on amphibians, reptiles, and mammals, but personal observation suggests that bird and turtle eggs may also be important in the diet. The death feigning behavior (bottom photo) seen in these snakes and its relatives seems to be an artifact of a diet that includes toxic toads and enlarged adrenal glands. This species prefers short grass prairies with sandy soils. |
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| Eastern Hognose Snake, Heterodon platirhinos Latreille, 1801. Top two photos: Union County, Illinois. Third photo: Will County, Illinois. Bottom Photo: Menard County, Illinois. The Eastern Hognose Snake inhabits much of the eastern USA from the eastern seaboard to the Great Plains. It prefers sandy soil habitats where it hunts toads and other anurans. Defense behavior includes spreading a hood and hissing, before it performs a death feigning display. It has been hypothesized that the elongated rear fangs of this snake are used to puncture toads as they are swallowed, but they also deliver a dose of venom and digestive enzymes. |
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| The North American Thirst Snakes have been considered relict species of one or more radiations, however, Vidal et al. (2007 C. R. Biologies 330:182-187) used nuclear gene sequences to show that they form a subfamily of the Dipsadidae. There are five genera and nine species currently recognized in this subfamily. That number can be expected to increase. These snakes are quite diverse in terms of their morphology and ecology, ranging from snakes that are less than 500 mm to snakes that are almost 2 m, and snakes that are fossorial, terrestrial, and aquatic. All of the species in this group are oviparous (egg laying). In terms of diet, they are also highly variable, with some specialists feeding only on aquatic salamanders or toads, and yet others more dietary generalists. |
