Eastern Worm Snake

Eastern Worm Snake
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Subfamily: Xenodontinae
Genus: Carphophis
Trinomial name
Carphophis amoenus amoenus
(Say, 1825)
Synonyms

Coluber amoenus Say, 1825
Calamaria amoena Schlegel, 1837
Brachyorrhos amoenus Holbrook, 1842
Celuta amoena Baird & Girard, 1853
Carphophis amoena Gervais, 1843
Carphophis amœnus Boulenger, 1894
Carphopiops amoenus Cope, 1900
Carphophis amoena amoena Schmidt & Davis, 1941
Carphophis amoenus amoenus Wright & Wright, 1957

The Eastern worm snake (Carphophis amoenus amoenus) is a nonvenomous colubrid found in the Eastern United States.[1]Carphophis amoenus amoenus or the Eastern worm snake can be found east of the Mississippi, from Southwest Massachusetts down to Southern Alabama across to Louisiana and then up to Illinois.[2] This species of snake has a large range that it covers and normally prefers a moist habitat in the rocky woodlands, under rotten wood of logs and stumps.[3] Though this snake is quite abundant over its range, it is rarely seen for its dormant lifestyle and where it usually resides. This snake is most common on the edges or in the ecotonal areas of open to thick woodlands, and the borders of wetlands. It may also be found in the grasslands that are next to woodlands. The best chance to spot C. amoenus amoenus is after heavy rains, when it’s small size and distinct color make it easy to spot. This species prefers moist soil that is inhabited by earthworms, which are its main prey; so the soil needs to be sufficiently moist. The snake’s skin naturally evaporates water; so the soil needs to me moist enough to offset this also. C. amoenus amoenus is mostly found under rocks and in sufficient leaf litter during the extreme day time heat.[2]

Contents

Diagnosis

The Eastern worm snake is a small snake. Adults are 19–28 cm (7½–11 in.) in total length, record 34 cm (13¼ in.).[4] It is brown dorsally, and bright pink ventrally, with the belly color including one or two dorsal scale rows.[5] The dorsal scales are smooth, in 13 rows. It has five upper labials and one postocular.[6]C. amoenus coloration is unpatterned and can be tan to dark brown in color, has a pointed head, and small black eyes. It has pinkish ventral pigmentation which extends dorsally onto dorsal scale rows one to two. The tail is short in comparison with its body and ends in an abrupt, spine-like scale.[2] Females are longer than males but have a shorter tail. The head is small, conical and no wider than the neck. Other small, unpatterned brownish snakes such as earth snakes (genus Virginia) and red-bellied snakes (Storeria occipitomaculata) both have keeled body scales but lack the spine-tipped tail. Other ways to distinguish between C. Amoenus and other species is that the body scales usually occur in 13 rows and are smooth, pitless, and the anal plate is split.[3][7] Another snakes that is commonly confused with C. amoenus is the western worm snake (Carphophis vermis), which used to be considered a subspecies of C. amoenus, and has the slight ventral pigmentation extending onto the third body scale row, and a dark gray or gray-violet dorsum. The southeastern crowned snake (Tantilla coronata) has 15 midbody scale rows, a dark head, and a dark collar.[2]

General Description and Taxonomy

There are two subspecies of Carphophis amoenus: Carphophis amoenus amoenus and Carphophis amoenus helenae. Carphophis amoenus amoenus, the eastern worm snake, is found from Rhode Island, southwestern Massachusetts, and southeastern New York south to South Carolina, northern Georgia, and central Alabama. It has separate internasal and prefrontal scales.[2] No gular scales occur between the posterior chin shields. Each maxilla has 9–12 small teeth. The single hemipenis has a forked sulcus spermaticus and 3 large basal spines. Adult males have ridges on the body scales that are dorsal to the anal plate. The young of this species are always much darker than the parent; then during the second year they change from a dark gray to the brown of the adult specimen.[3] C. amoenus amoenus is almost exclusively an earthworm predator, but has also been known to consume other prey, from slugs to small salamanders. Due to human activities, C. amoenus amoenus is becoming rare in some areas. It is currently protected as threatened in Massachusetts and as a species of special concern in Rhode Island.[2]

Ecology

It is found in SW Connecticut, SE New York, New Jersey, SE Pennsylvania, Delaware, Maryland, Virginia, E West Virginia, North Carolina, South Carolina, N Georgia, N Alabama, and in the Appalachian Mountains of Kentucky and Tennessee.[8] The Eastern worm snake is a burrower, and is seldom seen.[9] The annual activity period of the worm snake varies with latitude and elevation. Some have found them active in every month but February on the coastal plain of South Carolina. Farther north C. amoenus amoenus is active from March–April to October- November. Few are surface active in the summer, but a second lesser period of activity occurs in the fall. Then to escape overheating or desiccation, it has adopted a fossorial lifestyle and it usually spends most of the year underground or in rotting logs.[2] They are normally found in forests with high leaf litter and canopy cover.[10] They generally remain inactive during extreme temperatures. They burrow by working the small, pointed head into cracks and crevices. Activity periods begin mainly in the late afternoon and early evenings and rarely last more than 12 hours.[7] C. amoenus amoenus does not move much but has been seen traveling 45m in a 24 hour period.[11] Males travel much farther than females and the diet consists of primarily of earthworms but may also include other soft-bodied invertebrates such as insect larvae.[7]

Predators include other snakes, thrushes, American robins, barn owls, and opossums.[7] Occasionally accidents kill C. amoenus amoenus, flooding of the lowlands and other natural disasters have been known to affect the population.[12] Some die as a result of human habitat destruction, and insecticide poisoning occasionally kill the snake. Eastern worm snakes release a foul-smelling liquid from the vent when handled, but they are completely harmless to humans and rarely even attempt to bite.[7] C. amoenus amoenus is very shy and mild mannered. The normal behavior of the snake when handled is to twist, then try to crawl between the fingers, probe the hand with their tail spine, and emit the strong-smelling liquid.[2]

Reproduction

It is not known for certain but courtship and mating probably occur in the spring; the authors have most often found the sexes together between late April and June. Then the developing eggs can be seen through the translucent venter of the female in late May and June. Oviposition takes place between early June and mid-July, 5 June to 15 July in northern Virginia.Eggs are laid in late June or early July, 2–8 per clutch. The eggs are smooth and elongate, 16–25 mm (⅝–1 in.) long by 7–8 mm (¼ in.) wide. Often one end of an egg is wider than the other. Hatching occurs in August or early September. Hatchlings are about 100 mm (4 in.) in total length.[8] They are darker than adults.[4] The authors have found clutches of eggs in depressions under rocks, in cavities in the rotting wood of logs and stumps, and in an old sawdust pile; and rodent burrows are probably also used for nesting. A female was nearby or with the eggs in 75% of the cases.[2]

Populations

C. amoenus amoenus may occur in large numbers where the habitat is ideal. C. Ernst and his students collected 108 individuals from beneath rocks and debris in 100 m along a hillside overlooking the Kentucky River in on hour on an April Afternoon. It is the most common snake in northern Virginia, and at one site there occurs in densities over 200/ha. The 1.88:1.00 sex ratio of a juvenile population in South Carolina significantly favored males (64) over females (34), though the ratio of adults that were caught in northern Virginia is not significantly different from 1:1.[2]

References

  1. ^ "Maryland DNR, "All About Snakes in Maryland"". http://www.dnr.state.md.us/wildlife/snakeinfo.asp. 
  2. ^ a b c d e f g h i j Ernst CH, Ernst EM. 2003 ‘’Snakes of the United States and Canada’’, “Carphophis amoenus” pp. 53–56; Smithsonian Books,Washington, London
  3. ^ a b c Ernst CH, Barbour RW; 1989, ‘’Snakes of Eastern North America’’, "Carphophis amoenus" pp. 15–17, George Mason University Press, Fairfax, Virginia
  4. ^ a b Conant, Roger. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America, 2nd edition. Houghton Mifflin. Boston.
  5. ^ Schmidt, K.P. and D.D. Davis. 1941. Field Book of Snakes of the United States and Canada. G.P. Putnam's Sons. New York.
  6. ^ Smith, H.M. and E.D. Brodie, Jr. 1982. A Guide to Field Identification: Reptiles of North America. Golden Press. New. York.
  7. ^ a b c d e Croshaw DA, Jensen JB, Camp CD, Gibbson W, Elliott MJ; 2008 ‘’Amphibians and Reptiles of Georgia’’ , “Eastern Worm Snake”, pp. 328–329, University of Georgia Press, Athens, Georgia
  8. ^ a b Wright, A.H. and A.A. Wright. 1957. Handbook of Snakes of the United States and Canada. Comstock. Ithaca and London.
  9. ^ Zim, H.S. and H.M. Smith. 1956. Reptiles and Amphibians: A Guide to Familiar American Species, A Golden Nature Guide. Simon and Schuster. New York.
  10. ^ Sutton, WB.; Wang, Y; Schweitzer, CJ (2010). "Habitat relationships of reptiles in pine beetle disturbed forests of Alabama, USA with guidelines for a modified drift-fence sampling method". Current Zoology 56 (4): 411–420. 
  11. ^ Barbour RW., Harvey MJ., Hardin JW. (1969). "Home Range, Movements, and Activity of Eastern Worm Snake, Carphophis amoenus amoenus". Ecology 50 (3): 470. 
  12. ^ Russell KR, Hanlin HG (1999). "Aspects of the ecology of worm snakes Carphophis amoenus associated with small isolated wetlands in South Carolina". Journal of Herpetology 33 (2): 339–344. doi:10.2307/1565739. JSTOR 1565739.