Corn snake

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Corn snake
Kornnatter.jpg
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Subphylum:Vertebrata
Class:Reptilia
Subclass:Lepidosauria
Order:Squamata
Suborder:Serpentes
Family:Colubridae
Subfamily:Colubrinae
Tribe:Lampropeltini
Genus:Pantherophis
Species:P. guttatus
Binomial name
Pantherophis guttatus
(Linnaeus, 1766)
Pantherophis guttatus map.svg
Synonyms
 
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Corn snake
Kornnatter.jpg
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Subphylum:Vertebrata
Class:Reptilia
Subclass:Lepidosauria
Order:Squamata
Suborder:Serpentes
Family:Colubridae
Subfamily:Colubrinae
Tribe:Lampropeltini
Genus:Pantherophis
Species:P. guttatus
Binomial name
Pantherophis guttatus
(Linnaeus, 1766)
Pantherophis guttatus map.svg
Synonyms

The corn snake[3] (Pantherophis guttatus) is a North American species of rat snake that subdues its small prey by constriction. Corn snakes are found throughout the southeastern and central United States. Their docile nature, reluctance to bite, moderate adult size 3.9–6.0 feet (1.2–1.8 m), attractive pattern, and comparatively simple care make them popular pet snakes. In the wild, they usually live around 6–8 years, but in captivity can live to be up to 25 years old.[4] Though superficially resembling the venomous Copperhead and often killed as a result of this mistaken identity, Corn snakes are harmless and beneficial to humans.[5] Corn snakes lack venom and help control populations of wild rodent pests that damage crops and spread disease.[6] They can be distinguished from Copperheads by their brighter colours, slender build and lack of heat-sensing pits.[7]

The corn snake is named for the species' regular presence near grain stores, where it preys on mice and rats that eat harvested corn.[8] The Oxford English Dictionary cites this usage as far back as 1675. Some sources maintain that the corn snake is so-named because the distinctive, nearly-checkered pattern of the snake's belly scales resembles the kernels of variegated corn.[9][10] Regardless of the name's origin, the corn reference can be a useful mnemonic for identifying corn snakes.

Taxonomy[edit]

There are two subspecies of Pantherophis guttatus:

It has been suggested that Pantherophis guttatus can be split into three species: Pantherophis guttatus, Pantherophis emoryi (corresponding with the subspecies Pantherophis guttatus emoyi) and Pantherophis slowinskii (occurring in western Louisiana and adjacent Texas).[11]

Pantherophis guttatus was previously placed in the genus Elaphe, but Elaphe was found to be paraphyletic by Utiger et al., leading to placement of this species in the genus Pantherophis.[12] The placement of Pantherophis guttatus and several related species in Pantherophis rather than Elaphe has been confirmed by further phylogenetic studies.[13][14] Many reference materials still use the synonym Elaphe guttatus.[15] Molecular data has shown that Corn Snakes are actually more closely related to King Snakes (genus Lampropeltis) than they are to the Old World Rat Snakes with which they were formerly classified.

Natural habitat[edit]

Wild corn snakes prefer habitats such as overgrown fields, forest openings, trees, palmetto flatwoods and abandoned or seldom-used buildings and farms, from sea level to as high as 6,000 feet. Typically, these snakes remain on the ground until the age of 4 months old but can ascend trees, cliffs and other elevated surfaces.[16] They can be found in the southeastern United States ranging from New Jersey to the Florida Keys and as far west as Texas.

In colder regions, snakes hibernate during winter. However, in the more temperate climate along the coast they shelter in rock crevices and logs during cold weather, and come out on warm days to soak up the heat of the sun. During cold weather, snakes are less active and therefore hunt less.

Reproduction[edit]

Baby corn snakes hatching from their eggs

Corn snakes are relatively easy to breed. Although not necessary, they are usually put through a cooling (also known as brumation) period that takes usually 60–90 days long. This is to get them ready for breeding and to tell them that its time to reproduce. Corns brumate at around 10 to 16 °C (50 to 61 °F) in a place where they can not get disturbed and little sunlight.

Corn snakes usually breed shortly after the winter cooling. The male courts the female primarily with tactile and chemical cues, then everts one of his hemipenes, inserts it into the female, and ejaculates his sperm. If the female is ovulating, the eggs will be fertilized, and she will begin sequestering nutrients into the eggs, then secreting a shell.

Egg-laying occurs slightly more than a month after mating, with 12–24 eggs deposited into a warm, moist, hidden location. Once laid the adult snake abandons the eggs and does not return to them. The eggs are oblong with a leathery, flexible shell. Approximately 10 weeks after laying, the young snakes use a specialized scale called an egg tooth to slice slits in the egg shell, from which they emerge at about 5 inches in length.

Diet[edit]

Captive corn snake eating pinky mouse

Like all snakes, corn snakes are carnivorous, and in the wild they will eat every few days. While most corn snakes will seek and consume small rodents, such as the White-footed Mouse, they may also be found eating reptiles or amphibians, or climbing trees in order to find unguarded bird eggs.[17]

In captivity[edit]

Captive corn snake in hide box

Corn snakes are one of the most popular types of snakes to keep in captivity or as pets. Their size, calm temperament, and ease of care contribute to this popularity. Captive corn snakes tolerate being handled by their owners, even for extended periods of time.[18] A corn snake's space requirements are low since a medium sized vivarium provides enough room for a full grown corn snake. Corn snakes enjoy hiding and burrowing which is usually accommodated with a loose substrate (such as Aspen wood shavings or newspaper) and one or more hide boxes.[19] Captive corn snakes are generally fed pre-killed or stunned feeder mice. This is because captive-bred rodents reduce the risk of exposing the snake to pathogens or live prey-induced injuries.[20]

Variations[edit]

A docile young corn snake (an introduced species) captured from the wild on the island of Nevis, West Indies, in 2009.

After many generations of selective breeding, domesticated corn snakes are found in a wide variety of different colors and patterns. These result from recombining the dominant and recessive genes that code for proteins involved in chromatophore development, maintenance, or function. New variations, or morphs, become available every year as breeders gain a better understanding of the genetics involved.

Color morphs[edit]

Anerythristic A corn snake

Pattern morphs[edit]

Amelanistic Stripe corn snake

Compound morphs[edit]

There are tens of thousands of possible compound morphs. Some of the most popular are listed.

"Opal" phase corn snake

Scale mutations[edit]

Hybrids[edit]

Hybrids between corn snakes and any other snakes is very common within captivity and rarely occurs in the wild. Hybrids within the genera Pantherophis, Lampropeltis, or Pituophis so far have been proven to be completely fertile. There are many different corn snake hybrids bred in captivity. A few common examples include:

When hybrids of corn snakes are found in the wild they are usually hybridized with other Pantherophis species whose ranges overlap with corn snakes.

References[edit]

  1. ^ Stejneger L, Barbour T. 1917. A Check List of North American Amphibians and Reptiles. Cambridge, Massachusetts: Harvard University Press. iv + 125 pp. (Elaphe guttata, p. 82).
  2. ^ The Reptile Database. www.reptile-database.org.
  3. ^ Crother, B. I. (ed.). 2008. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, pp. 1–84. SSAR Herpetological Circular 37. PDF at SSAR. Accessed 4 July 2011.
  4. ^ "Corn Snake Fact sheet". 
  5. ^ "Corn Snake". 
  6. ^ "Did Someone Say Snakes?". 
  7. ^ "Reptiles and Amphibians of Virginia". 
  8. ^ "FLMNH - Eastern Corn Snake (Pantherophis guttatus)". 
  9. ^ PetCo Corn Snake Care Sheet
  10. ^ Smithsonian National Zoo Corn Snake Fact Sheet
  11. ^ Burbrink, F. T., 2002. Phylogeographic analysis of the corn snake (Elaphe guttata) complex as inferred from maximum likelihood and Bayesian analyses. Molecular Phylogenetics and Evolution 25: 465-476.
  12. ^ Utiger, U., N. Helfenberger, B. Schätti, C. Schmidt, M. Ruf, and V. Ziswiler, 2002. Molecular Systematics and Phylogeny of Old and New World ratsnakes, Elaphe Auct., and related genera (Reptilia, Squamata, Colubridae). Russian Journal of Herpetology 9(2): 105-124.
  13. ^ Burbrink, F. T. and R. Lawson, 2007. How and when did Old World rattle snakes disperse into the New World? Molecular Phylogenetics and Evolution 43: 173-189.
  14. ^ Pyron, R. A. and F. T. Burbrink, 2009. Neogene diversification and taxonomic stability in the snake tribe Lampropeltini (Serpentes: Colubridae) Molecular Phylogenetics and Evolution 52: 524-529.
  15. ^ Bartlett, Patricia; Bartlett, R. D. (2006-05-26), Corn Snakes and Other Rat Snakes, Complete Pet Owner's Manual (2nd ed.), Hauppauge NY: Barron's Educational Series, ISBN 978-0-7641-3407-4 
  16. ^ Peterson Field Guide - Western Reptiles and Amphibians - 3rd Edition
  17. ^ "ADW: Pantherophis guttatus: INFORMATION". University of Michigan Museum of Zoology. 
  18. ^ "The Corn Snake.co.uk". 
  19. ^ "The Corn Snake.co.uk - Care Sheet". 
  20. ^ "Corn Snake Care Sheet". South Mountain Reptiles. 
  21. ^ "CCCorns - Corn Snake Star Gazer Information Page". 

External links[edit]