Eastern worm snake

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Eastern worm snake
Carphophis amoenus amoenus.jpg
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Subphylum:Vertebrata
Class:Reptilia
Order:Squamata
Suborder:Serpentes
Family:Colubridae
Subfamily:Xenodontinae
Genus:Carphophis
Species:C. amoenus
Subspecies:C. a. amoenus
Trinomial name
Carphophis amoenus amoenus
(Say, 1825)
Synonyms
  • Coluber amœnus 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
 
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Eastern worm snake
Carphophis amoenus amoenus.jpg
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Subphylum:Vertebrata
Class:Reptilia
Order:Squamata
Suborder:Serpentes
Family:Colubridae
Subfamily:Xenodontinae
Genus:Carphophis
Species:C. amoenus
Subspecies:C. a. amoenus
Trinomial name
Carphophis amoenus amoenus
(Say, 1825)
Synonyms
  • Coluber amœnus 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 subspecies of non-venomous colubrid endemic to the Eastern United States.[1] The species' range extends from southwest Massachusetts, south to southern Alabama, west to Louisiana and north to Illinois.[2] This species is common in the ecotone between woodlands and wetlands. It may also be found in grasslands adjacent to woodlands.[3] Though this snake can be abundant in parts of its range, it is rarely seen because of its fossorial lifestyle. When not underground, C. a. amoenus resides mostly under rocks, logs and leaf litter, or burrowed within rotting woody debris.[2]

Description[edit]

C. amoenus is a small snake. Adults are 19–28 cm (7.5–11.0 in) in total length, with a record length of 34 cm (13 in).[4] The 13 rows of dorsal scales are smooth and glossy. It has five upper labials and one postocular scale.[5] C. amoenus is unpatterned and can be tan to dark brown in color. It has pinkish ventral pigmentation which extends onto dorsal scale rows one to two. The tail is short in comparison with its body and ends in a spine-like scale.[2] Females are longer than males, but have shorter tails. The head is small, conical and no wider than the neck. The eyes are reduced and black.

C. amoenus can be distinguished from the western worm snake (Carphophis vermis), by its less vibrant dorsal and ventral coloration and lack of ventral pigmentation on the third body scale row. Other small, unpatterned brownish snakes which may be confused with C. amoenus, such as earth snakes (genus Virginia) and red-bellied snakes (Storeria occipitomaculata), have keeled dorsal scales and lack the spine-tipped tail.[3][6] The southeastern crowned snake (Tantilla coronata) has 15 midbody scale rows, a dark head, and a dark collar.[2]

General description and taxonomy[edit]

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. The two subspecies can be distinguished by the internasal and prefrontal scales, which are unfused in C. a. amoenus and fused in C. a. helanae.[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 three large basal spines. Juveniles are darker than adults, with the dorsum changing from dark brown to tan, and the venter from dark pink to pale pink as individuals become larger.[3][4]

Geographic range[edit]

It is found in southern Arizona, southern Connecticut, southwestern Massachusetts, southeastern New York, New Jersey, southeastern Pennsylvania, Delaware, Maryland, Virginia, eastern West Virginia, North Carolina, South Carolina, northern Georgia and Alabama, and in the Appalachian Mountains of Kentucky and Tennessee.[7] It is currently protected as threatened in Massachusetts and as a species of special concern in Rhode Island.[2]

Ecology[edit]

The eastern worm snake is a burrower, and is seldom seen.[8] 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 active above ground in the summer, but a second, lesser period of activity occurs in the fall. 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.[9] They generally remain inactive during extreme temperatures. They burrow by working their small, pointed heads into cracks and crevices. Activity periods begin mainly in the late afternoon and early evenings and rarely last more than 12 hours.[6] C. amoenus amoenus does not move much but has been seen traveling 45m in a 24 hour period.[10] Males travel much farther than females and their diets consist primarily of earthworms, but may also include other soft-bodied invertebrates, such as insect larvae.[6]

Predators include other snakes, thrushes, American robins, barn owls, and opossums.[6] Occasionally, road traffic kills C. amoenus amoenus, and flooding of the lowlands and other natural disasters have been known to affect the population.[11] Some die as a result of human habitat destruction and insecticide poisoning. When handled, C. amoenus may release a foul-smelling musk from their cloaca, defecate, attempt to burrow between the fingers, and probe the hand with the tail spine.[2] However, they are completely harmless to humans and do not attempt to bite.[6]

Reproduction[edit]

Courtship and mating probably occur in the spring; the sexes are most often found 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, two to eight per clutch. Clutches are placed in depressions under rocks, in cavities in the rotting wood of logs and stumps, and in old sawdust piles. A female was nearby or with the eggs in 75% of the cases.[2] The eggs are smooth and elongated, 16–25 mm (0.63–0.98 in) long by 7–8 mm (0.28–0.31 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 (3.9 in) in total length.[7]

Populations[edit]

C. a. 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 one hour on an April afternoon. It is the most common snake in northern Virginia, and one site had 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 caught in northern Virginia was not significantly different from 1:1.[2]

References[edit]

  1. ^ "Maryland DNR, "All About Snakes in Maryland"". 
  2. ^ a b c d e f g h i j Ernst CH, Ernst EM. 2003. Snakes of the United States and Canada. Smithsonian Books. Washington and London. ("Carphophis amoenus", pp. 53–56.) ISBN 1588340198
  3. ^ a b c Ernst CH, Barbour RW. (1989) Snakes of Eastern North America. George Mason University Press. Fairfax, Virginia. ("Carphophis amoenus", pp. 15–17.) ISBN 0913969249
  4. ^ a b Conant, Roger (1975) A Field Guide to Reptiles and Amphibians of Eastern and Central North America, 2nd edition. Houghton Mifflin. Boston. ("Carphophis amoenus", pp. 174–175, Plate 25, Map 131.) ISBN 0395904528
  5. ^ Smith, H.M., and E.D. Brodie, Jr. (1982) Reptiles of North America: A Guide to Field Identification. Golden Press. New York. 240 pp. ("WORM SNAKE", pp. 162–163.)
  6. ^ a b c d e Croshaw DA, Jensen JB, Camp CD, Gibbson W, Elliott MJ (2008) Amphibians and Reptiles of Georgia. University of Georgia Press. Athens, Georgia. ("Eastern Worm Snake", pp. 328–329.) ISBN 0820331112
  7. ^ a b Wright, A.H., and A.A. Wright. 1957. Handbook of Snakes of the United States and Canada. Comstock. Ithaca and London. 1,105 pp. (in two volumes) ("WORM SNAKES Genus CARPHOPHIS Gervais", pp. 104–111, Map 12, Figures 21, 33-34.)
  8. ^ 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. ("Worm Snake", pp. 83–84.)
  9. ^ 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. 
  10. ^ Barbour RW., Harvey MJ., Hardin JW. (1969). "Home Range, Movements, and Activity of Eastern Worm Snake, Carphophis amoenus amoenus". Ecology 50 (3): 470. doi:10.2307/1933902. 
  11. ^ 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. 

Further reading[edit]