Friday, March 30, 2012

Venomous Snakes in Ohio?

Growing up in northeast Ohio I can remember being out with my friends in the woods looking for “cool critters”.  While we would collect tadpoles and catch frogs, we never stumbled upon a snake. Yet, as I patrolled off the trail in our woods into the unknown, my 9 year old self worried about an encounter with the deadly venomous snakes I had seen on Animal Planet and The Discovery Channel.  Such fears, I was told by parents, teachers, and other 9 year olds, were unfounded because “there aren’t venomous snakes in Ohio!  They’re all down south and out west!”. 

Myth:  There are no venomous snakes in Ohio.
Fact: There are three known species of venomous snakes native to Ohio.

It wasn’t until I took Herpetology at Miami University that I learned that there are three venomous snake species native to Ohio:  the timber rattlesnake (Crotalus horridus), the eastern massausaga snake (Sistrurus catenatus), and the northern copperhead snake (Agkistrodon contortrix).  I thought it might be useful to give a brief overview of each species.

Family:  Viperidae

Scientific:  Agkistrodon contortrix

Common Name:  Northern copperhead

Counties found in Ohio (since 1976): Adams, Scioto, Jackson, Meigs, Vinton, Athens, Hocking, and Washington.

Description:  The northern copperhead can be easily identified by its reddish, copper-colored head followed by a pink-light brown body with a dark brown hourglass pattern. As with all poisonous snakes, it has a triangulated head with elliptical eyes and a heat sensing loreal pit.  Its average size varies between 24-36” long.  

Habitat:  The copperhead thrives in a number of areas including: oak-hickory hillsides with plenty of rock crevices, swamp boarders, and foundations from old, abandoned buildings.  They show a strong preference to moist habitats.

Diet:  Primary food is mice.  However, they will consume small birds, frogs, and other small snakes.

Behavior:  The copperhead is a “social” snake in that it will overwinter in communal dens with both its own kind and other species.  These overwintering dens are usually near a rocky ridge on a south-facing slope.  As with most snakes, copperheads are generally not aggressive, and their bites are rarely fatal.  They are most active during their two mating seasons: Late February-April and Late August-October.

Conservation Status: Least concern

Family: Viperidae

Scientific: Crotalus horridus

Common name: Timber rattlesnake

Counties found in Ohio (since 1976):  Adams, Scioto, Pike, Jackson, Gallia, Vinton, Hocking, and Ross.

Description:  The average adult timber rattlesnake in Ohio is around 38-40” long, although they have been recorded to be as long as 60”.  They experience two distinct color phases: the young are typically yellow with a black and brown “chevron-like” pattern, while the adults typically will have much darker, almost black, skin, but still with the brown “chevron like” pattern.  As with all poisonous snakes, it has a triangulated head with elliptical eyes and a heat sensing loreal pit.  As characteristic of a rattlesnake, its tail has a rattle, which begins to develop after the first time it sheds its skin, that it uses to warn trespassers of its presence.

Habitat: Timber rattlesnakes require rocky hillsides with underground crevices for overwintering a “summer” habitat consisting of mixed deciduous forest with lots of leaf-litter, some fallen trees, and a mostly closed canopy for cover.  The average home range for males, females (barren), and pregnant females has been reported to be around 160, 42, and 9 acres, respectively.

Diet:  Timber rattlesnakes are “sit and wait” predators.  Their venom works by causing massive hemorrhaging (bleeding) in their prey.  They will let their prey escape and bleed to death.  Then, using chemosensory cues, it will follow the scent trail to its meal.  Timber rattlesnakes have been known to eat shrews, moles, bats, mice, rats, chipmunks, squirrels, rabbits, and birds.

Behavior:   Generally considered relatively docile and will prefer to escape rather than attack.  However, if provoked it will attack/behave aggressively.  However, due to already low population numbers and their secretive nature, the chances of running into one of these snakes is very low.

Conservation Status:  Endangered. Timber rattlesnakes don’t reach maturity until later in life (around 11 years) and females only reproduce a few times in life.  Combine this with habitat destruction and you have a recipe for population decline.

Family: Viperidae

Scientific:  Sistrurus catenatus

Common Name: Eastern massausauga

Counties found in Ohio (since 1976): Warren, Clark, Champaigne, Licking, Wyandot, Wayne, Trumbull, and Ashtabula

Description: Small (18-24”) and stout bodied, the eastern massasauga snake varies in color from brownish gray to black with dark blotches running the length of the body.  In addition to the 29-50 dorsal blotches, three smaller rows of dark spots can be seen on both sides of the body.  As with all poisonous snakes, it has a triangulated head with elliptical eyes and a heat sensing loreal pit. As with the timber rattlesnake, the eastern massasauga has a rattle.

Habitat:  The word “massasauga”  is derived from the Chippewa Indian language and refers to marshy areas associated with the mouth of a river.  Fittingly, today’s populations in Ohio persist in bogs, swamps, and wet praries.  They prefer low lying, poorly drained meadows.  They will overwinter in moist soil areas.  Their home range is relatively small (11,753 yards), and they only move around 30 feet per day.  They can be found resting under flat boards or other discarded material, and they bask in the sunlight in openings and clearings.

Diet:  Small mammals, other small snakes, frogs, salamanders, toads, and young birds

Behavior:  Very sluggish and will rarely make an attempt to bite unless they have been aroused.  Venom is extremely poisonous, but typical bites do not usually deliver enough to be fatal.  Both males and females are known to be most active at night.  They will also remain active in the day when the temperature is optimal.  They are most active and easily found in April, May, and October.

Conservation Status: Listed as endangered in Ohio.  These snakes were believed to have once inhabited all of the scattered prairies in Ohio, but extensive farming drastically reduced their numbers.

1 comment:

To Love What is Mortal said...

Thanks...although I have heard no venomous snake has been caught in Butler County for nearly 40 years, from a herpetologist. I'm surprised people think there are *no* venomous snakes in OH, since usually people think nonvenomous snakes are venomous!