Constriction

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Constriction is a method used by various snake species to kill their prey. Although some species of venomous and mildly venomous snakes do use constriction to subdue their prey, most snakes which use constriction lack venom.[1] The snake initially strikes at its prey and holds on, pulling the prey into its coils or, in the case of very large prey, pulling itself onto the prey. The snake will then wrap one or two coils around the prey. The snakes then monitor the prey's heartbeat to ascertain when it's dead.[2]

A Rainbow Boa (Epicrates cenchria cenchria) constricting and swallowing a mouse

Contrary to myth, the snake does not crush the prey, or even break its bones. It is generally accepted that snakes hold tightly enough to prevent the prey from drawing air into its lungs, resulting in death from asphyxia.[3] It has also been suggested that the pressure of constriction causes a rise in the pressure in the prey's body cavity greater than the heart can counter, resulting in immediate cardiac arrest.[4] This new hypothesis has yet to be confirmed, but data indicates that snakes can exert enough pressure for this mechanism to be plausible.[5]

Certain groups of snakes have characteristic patterns of constriction, including the number of coils they use and the orientation of the coils.[6]

Venomous snakes that also use constriction include the mussuranas (ophiophagous South American mildly venomous rear-fanged colubrids which uses constriction to subdue snakes including pit vipers), the western terrestrial garter snake (North American colubrid which is an inefficient constrictor and, like most Thamnophis garter snakes, mildly venomous),[7][8] some species of Boiga snakes (Asian and Australian rear-fanged colubrids) including the brown tree snake (Boiga irregularis),[9][10][11] and some species of Australian elapids, including some of the venomous Pseudonaja brown snakes and one Australian coral snake Simoselaps, and a few Australian colubrids.[12]

See also[edit]

References[edit]

  1. ^ Shine, R.; Schwaner, T. (1985). "Prey Constriction by Venomous Snakes: A Review, and New Data on Australian Species". Copeia 1985 (4): 1067–1071. JSTOR 1445266. 
  2. ^ Powell, Devin (25 Feb 2012). "Boas take pulse as they snuff it out". Science News. Retrieved 11 May 2014. 
  3. ^ "ADW: Boa constrictor: INFORMATION". Retrieved 10 May 2014. 
  4. ^ Hardy, David L. (1994). A re-evaluation of suffocation as the cause of death during constriction by snakes. Herpetological Review 229:45-47.
  5. ^ Moon, 2000. The mechanics and muscular control of constriction in gopher snakes (Pituophis melanoleucus) and a king snake (Lampropeltis getula). Journal of Zoology 252 : 83-98. http://www.ucs.ull.edu/~brm2286/Moon_2000_constriction.pdf
  6. ^ Willard, D. E. (1977). "Constricting Methods of Snakes". Copeia 1977 (2): 379–382. JSTOR 1443922. 
  7. ^ Alan de Queiroz and Rebecca R. Groen. "The inconsistent and inefficient constricting behavior of Colorado Western Terrestrial Garter Snakes, Thamnophis elegans."Journal of Herpetology, Vol. 35, No. 3 (Sep., 2001), pp. 450-460.
  8. ^ Patrick T. Gregory, J. Malcolm Macartney, and Donald H. Rivard. "Small mammal predation and prey handling behavior by the wandering garter snake Thamnophis elegans." Herpetologica. 36 (1): 87-93
  9. ^ Alan de Queiroz and Rebecca R. Groen. "The inconsistent and inefficient constricting behavior of Colorado Western Terrestrial Garter Snakes, Thamnophis elegans."Journal of Herpetology, Vol. 35, No. 3 (Sep., 2001), pp. 450-460.
  10. ^ CHISZAR, D. A. 1990. The behavior of the brown tree snake: a study in applied comparative psychology. In D. A. Dewsbury (ed.), Contemporary Issues in Comparative Psychology, pp. 101-123. Sinauer Assoc, Inc., Sunderland, MA.
  11. ^ http://www.fort.usgs.gov/resources/education/bts/bioeco/btsnake.asp
  12. ^ Shine, R.; Schwaner, T. (1985). "Prey Constriction by Venomous Snakes: A Review, and New Data on Australian Species". Copeia 1985 (4): 1067–1071. JSTOR 1445266.