Gray ratsnake

Gray ratsnake
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Genus: Pantherophis
Species: P. spiloides
Binomial name
Pantherophis spiloides
(A.M.C. Duméril, Bibron,
& A.H.A. Duméril, 1854)
Synonyms
  • Elaphis spiloides A.M.C. Duméril, Bibron, & A.H.A. Duméril, 1854
  • Coluber spiloides
    Günther, 1858
  • Elaphe obsoleta spiloides
    A.H. Wright & A.A. Wright, 1957
  • Elaphe spiloides
    Burbrink, 2001
  • Pantherophis obsoletus spiloides
    D. Schmidt & Kunz, 2005
  • Scotophis spiloides
    Collins & Taggart, 2008
  • Pantherophis spiloides
    Pyron & Burbrink, 2009

The gray ratsnake or gray rat snake (Pantherophis spiloides),[1] also commonly known as the central ratsnake, chicken snake, midlands ratsnake, or pilot black snake, is a species of nonvenomous snake in the genus Pantherophis in the subfamily Colubrinae. The gray ratsnake is one of about ten species within the Pantherophis genus of American rat snakes.

Description

Detail of head
Juvenile skin pattern

A medium to large serpent, gray rat snakes typically reach an adult size of 99–183 cm (39–72 in); however, the record is 215 cm (85 in). Unlike other Pantherophis, whose conspicuous juvenile pattern fades into adulthood, gray ratsnakes in the southern part of their range do not undergo drastic ontogenetic changes in color or markings. These snakes retain the juvenile pattern of dark elongate dorsal blotches separated by four, or more, pale gray body scales, a light gray crown with dark striping that forms an anteriorly facing spearpoint, and a solid band which covers the eyes and extends rearward to the posterior upper labial scales. However, in the northern part of their range they are black in adulthood, like P. alleghaniensis and P. obsoletus. The venter is usually off-white or pale gray with darker irregular blotches, and a double row of black spots behind the divided anal plate of the vent. The dorsal scale rows around midbody are usually weakly keeled. Because the gray ratsnake shares its range with other members of its genus, hybrids of midlands x eastern ratsnakes are not uncommon.

Geographic range and habitat

Native to North America, Pantherophis spiloides is commonly found in the forests of eastern and central United States. It occurs relatively continuously throughout the major part of the eastern half of the United States, along the western edge of the Appalachian Mountains, from southwestern New England to the Gulf of Mexico, westward to the Mississippi River, and northward from northern Louisiana to southwestern Wisconsin.

In Canada, this species is known to occur in two disjunct regions of southern Ontario: the Carolinian forest region along the north shore of Lake Erie in the southwest, and the Great Lakes/St. Lawrence region in the southeast.[2][3]

Behavior

An agile climber, gray ratsnakes are at home from the ground to the tree tops in many types of hardwood forest and cypress stands, along tree-lined streams and fields, and even barns and sheds in close proximity to people. Within its range, almost any environment rich in rodents, and vertical escape options, proves a suitable habitat for the gray ratsnake. As scent-hunters these powerful constrictors feed primarily on rodents, birds, and their eggs as adults, while neonates and juveniles prefer a diet of frogs and lizards. When startled, this species, like other ratsnakes, stops and remains motionless with its body held in a series of wave-like kinks. The gray ratsnake will defend itself by raising its head and bluffing a strike. If handled, these snakes will musk a victim by releasing the foul-smelling contents of their cloaca, and will bite if necessary. However, the gray ratsnake is less likely to bite than other members of its genus, and wounds from a bite rarely require more than a small bandage.

Reproduction

Breeding in P. spiloides takes place from April to July. Females deposit 5 to 27 eggs around mid-summer, and the 25–30 cm (9.8–11.8 in) hatchlings usually emerge in September.

Conservation status

The gray ratsnake is considered common across much of its range, but is listed as "of special concern" in Michigan [4] and is also listed as rare in Wisconsin.[5] Gray ratsnakes are listed federally in Canada as "endangered" (Carolinean population) and "threatened" (Great Lakes/St Lawrence population).[6] In the state of Georgia, all indigenous, nonvenomous snakes are illegal to kill or capture, and are considered to be in the custody of the Georgia Department of Natural Resources.[7]

References

  1. Pantherophis Fitzinger, 1843—North American Ratsnakes". in Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, With Comments Regarding Confidence In Our Understanding. Edition 6.1 Last updated: 24 May 2011.
  2. Species at Risk Public Registry – Species Profile (Gray Ratsnake). Sararegistry.gc.ca. Retrieved on 2013-08-24.
  3. Gray Ratsnake, Ontario Nature
  4. Gray ratsnake, Michigan Department of Natural Resources
  5. Gray ratsnake, Wisconsin Department of Natural Resources
  6. Canada Species At Risk Act
  7. Georgia Wildlife.org Keeping Georgia Wildlife as Pets. georgiawildlife.org

Further reading

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