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Smooth Green Snake

Opheodrys vernalis

What do they look like?

Smooth green snakes are the only snakes in eastern North America that are entirely bright green on their upper surfaces. This coloration camouflages them well in their grassy habitats. The head is slightly wider than the neck and is green above and white below. The belly is white to pale yellow. Occasionally smooth green snakes can be brown or tan in coloration. The scales are smooth and total body length ranges from 30 to 66 cm. Males are usually smaller than females, but have longer tails. Newly hatched smooth green snakes measure 8.3 to 16.5 cm in length and tend to be less brightly colored than adults, often olive-green or bluish-gray. Smooth Green snakes are harmless snakes, they are not venomous.

  • Sexual Dimorphism
  • female larger
  • sexes shaped differently
  • Range length
    30.0 to 66.0 cm
    11.81 to 25.98 in

Where do they live?

Smooth Green snakes are are only native to the Nearctic region. They are found from northeastern Canada, west to Saskatchewan, south through Illinois and Virginia. There are isolated populations in areas of the western United States as well, including Wyoming, New Mexico, Iowa, Missouri, Colorado, Texas, and northern Mexico.

What kind of habitat do they need?

Smooth Green snakes are found in moist, grassy areas, usually in prairies, pastures, meadows, marshes, and lake eges. They can also be found in open forested areas. They are most often found on the ground or climbing in low bushes. They also bask on and hide beneath rocks, logs, and other debris.

  • Aquatic Biomes
  • lakes and ponds

How long do they live?

Lifespans in the wild of Smooth Green snakes are unknown. One captive individual lived for 6 years.

  • Range lifespan
    Status: captivity
    6.0 (high) years

How do they behave?

Smooth Green snakes are active from April through October and are mainly solitary. In winter they hibernate with groups of other snakes, including other snake species. Hibernation sites include anthills and abandoned rodent burrows. Smooth Green snakes are most active during the day, though they may be active mainly in the morning and evening in hot weather.

How do they communicate with each other?

As other snakes, Smooth Green snakes rely mainly on their sense of smell, vision, and their detection vibrations to locate prey. They mainly communicate with other snakes by chemical cues and through body language.

What do they eat?

Smooth green snakes eat mainly insects. They prefer crickets, grasshoppers, and caterpillars, and will also eat beetles, spiders, centipedes, millipedes, snails, slugs, and sometimes amphibians.

What eats them and how do they avoid being eaten?

Smooth green snakes are probably eaten by birds, such as hawks and American crows, by large snakes, such as milk snakes, and by some mammals, such as raccoons and foxes. They rely on their bright green color to camouflage them under most circumstances. They are fast and agile and can escape quickly, but will bite and thrash if harassed and can smear attackers with a nasty-smelling fluid.

What roles do they have in the ecosystem?

Smooth Green snakes influence the populations of their insect prey and serve as a food source for predators.

How do they interact with us?

Smooth Green snakes help to control populations of insect pests where they are abundant.

  • Ways that people benefit from these animals:
  • controls pest population

Are they endangered?

Smooth Green snakes have been declining in numbers and local populations have been wiped out throughout their range. This is mainly the result of habitat destruction and pesticide use. Because their diet is mainly insects, they are particularly vulnerable to the effects of insecticides that are widely sprayed in agricultural areas.

Some more information...

Smooth Green snakes, as with most snakes, don't do well in captivity. They fail to eat and do not survive for long.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

carnivore

an animal that mainly eats meat

diurnal
  1. active during the day, 2. lasting for one day.
female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

young precocial

young are relatively well-developed when born

References

Harding, J. 1997. Amphibians and Reptiles of the Great Lakes Region. Ann Arbor, Michigan: University of Michigan Press.

 
University of Michigan Museum of ZoologyNational Science Foundation

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. "Opheodrys vernalis" (On-line), Animal Diversity Web. Accessed April 21, 2014 at http://www.biokids.umich.edu/accounts/Opheodrys_vernalis/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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