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Smooth Green Snake
Opheodrys vernalis
Pope County,
MN
Pope County, MN
Pope County, MN
Status
No status assigned in Minnesota.
Description
This snake is not likely to be confused
with any other snake in Minnesota. It is 12-22 inches in length
and non venomous. It has no outstanding markings, but it is
a bright, brilliant green. The belly is usually bright yellow,
but sometimes may be cream instead. The labials are the color
of the belly. The scales are smooth (hence the name) and the
anal plate is divided.
Subspecies
No subspecies of Opheodrys
vernalis are recognized any longer.
Range
The Smooth Green Snake is found in scattered
populations in Minnesota. It's range once supposedly spanned
across most of Minnesota and much of north central and northeastern
North America. Now it is greatly reduced to various blotches
scattered throughout its natural range. In Minnesota, this
snake apparently follows the Mississippi and Crow Wing Rivers
as most records form a line from northwestern to southeastern
Minnesota. Isolated records from relatively distant counties
indicate populations left from a larger range in the past.
Habitat
The Smooth Green Snake is found in a variety
of habitats such as grassy, moist meadows, native praries,
and clearings in coniferous pine forests. The snake is seen
crossing bike or hiking trails, or brought home by cats or
dogs that hunt in large open field, particularly near railroad
tracks.
Habits
This snake is largely dinural and less
secretive than our other small snakes. It spends most of its
day forging through tall grass or small shrubs and though
it is an accomplished climber, it is mostly terrestrial. It
does not spend as much time under cover as other Minnesota
snakes, but do not underestimate the effectiveness of searching
under boards, flat rocks, or other objects for these snakes.
When approached in the field, these snakes take off for a
short distance then "freeze" or gently sway with the grass,
perfectly camouflaged. Most are discovered only when they
venture onto the road. When they are picked up they may thrash
for a bit, but they rarely bite. I have witnessed an interesting
behavior in one specimen. It twisted about and opened its
mouth and feigned death. When it was left alone, it tried
to crawl away normally. Once disturbed again, it resumed the
act. Persons finding a dead small, "blue" snake mistake it
for a racer (Coluber sp.). If it was a racer the size of an
adult green snake, it should have a spotted juvenile pattern.
After death, green snakes turn blue in dorsal coloration.
Yellow and blue pigments in the skin fuse to produce the bright
green color in the living snakes. After death, the yellow
pigment breaks down very quickly, whereas the blue pigment
is more stable and remains much longer. This is also why garter
snakes (Thamnophis sp. ) that have been dead for a while have
blue dorsal and lateral stripes.
Green Snakes hibernate in burrows, rock
crevices, road embankments, and (in northern Minnesota), ant
mounds (Lang, 1969). Large numbers of green snakes have been
found together with redbelly and plains garter snakes hibernating
in these mounds.
Breeding occurs in spring. They are oviparous
laying 3-15 eggs in a clutch. Several females may nest together.
Incubation and laying varies greatly among individuals. Some
female green snakes may not lay the eggs until a week or even
days before they hatch. Some have retained the eggs until
they hatch inside the female like ovovivparous snakes. A friend
of mine and I have found green snake eggs under a railroad
tie in westen Wisconsin. They had grown to the size of milk
snake (Lampropeltis triangulum) eggs! They hatched in about
a month. The young were 4-5 inches long and noticeably darker
than the adults.
Food
Green Snakes are one of the few species
of snake that is entirely insectivorous. They like crickets,
grasshoppers, and smooth caterpillars. This is probably one
of the reasons this snake has declined in abundance. Along
with habitat destruction, pesticides have undoubtedly reduced
these snakes to the isolated populations they now exist in.
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