PROFILES IN NATURE
Venomous or Non-Venomous?
I ran this column last summer but I feel it is important enough
to repeat each year during warm weather. I usually get several phone
calls and text per year asking if a certain snake that was found is
dangerous or not. I don’t mind these calls at all but am just trying to
get this information out there. If anyone needs a refresher this same
information is available on my web site,
www.kentuckyupclose.com.
With a couple of months of
warm weather left and hunting seasons right around the corner more and
more people will be enjoying the outdoors. I thought this might be a
good time to clarify some sure methods on how to tell if a snake is
dangerous or not.
Although five families or groups of snake occur in North America
only two are present in Kentucky and the bordering states. The
Colubridae, or
colubrids, and the Viperidae, or pit viper family. Since we are only
dealing with two families and each has its own distinctive
characteristics, telling a venomous snake from a non-venomous snake is
quiet easy.
Out of the 31 species (40 or so if sub-species and intergrades
are counted) of snake present in Kentucky all but four belong in the
colubrid Family and are our non venomous species. These include rat
snakes, kingsnakes, hog-nosed snakes, water snakes, garter snakes, and
several other smaller groups.
The four venomous snakes present in Kentucky are pit vipers and
are the copperhead, water moccasin or cottonmouth, timber rattlesnake,
and pigmy rattlesnake. The pigmy rattlesnake is only present in Kentucky
in the southern portion of the Land Between the Lakes and Trigg County
areas.
First, lets discuss a common but untrue method of identifying a
venomous snake. Probably the most common statement I hear is “poisonous
snakes have blunt tails”. This is an absolute untruth. All of our snakes
are born with sharp tails. The only ones that have blunt tails are the
ones that have lost the tip to a predator or an over-zealous housewife
with a garden hoe!
Now for the three absolute methods to tell if a Kentucky Snake is
venomous or not.
1.)
Pupils;
All of our colubrid (non-venomous) snakes have round pupils. All of our
pit vipers (venomous) snakes have elliptical or “cats eye” shaped
pupils.
2.)
Heat
sensing pits; All of our pit vipers (venomous) have a pit located
between the eye and the nostril on each side of the head. This pit
allows the snake to see an infrared image in total darkness. This is
useful as well for locating warm blooded prey such as mice. All of our
colubrids (non poisonous) lack these pits.
Photo
Credit –
www.kentuckyupclose.com
3.)
Tail
scales; All of our our snakes have single scales across the belly until
reaching the anal plate. The anal plate is the scale that covers the
vent opening. The anal plate may be single or divided. All of our
colubrids (non-venomous) snakes start having divided scales immediately
following the anal plate. All of our pit vipers (venomous) have a series
of scales that are not divided immediately following the anal plate.
This may consist of a few scales or most of the tail section.
Photo
Credit –
www.kentuckyupclose.com
Last are a couple of
methods that although are factual can be misleading.
1.)
Head
shape; All of our pit vipers have a spade or arrow-head shaped head with
a narrow neck that then widens into the main body. Most of our non
venomous snakes heads are no wider than the neck and lack the spade
shape. A few of our larger non-venomous snakes such as the
diamond-backed water snake, appear to have a wider than usual head, add
to the fact that a lot of species flatten their head and body and this
trait can become misleading.
2.)
Cross
section of the body; A cross section view of all our pit vipers
(venomous) have a roughly triangle shaped body. Our colubrids
(non-venomous) are more rounded or oval. The problem with this is that
as mentioned before several of the non-venomous species flatten their
body when disturbed and would then appear to have the triangle cross
section.
One interesting fact to note is if you find a shed skin that is
intact it can be easily determined if it came from a poisonous or
non-poisonous species. The scales on the tail section are a dead
giveaway and if examined closely the pits or lack thereof are also a
telltale sign.
The methods I have listed here are accurate in Kentucky and
bordering states. Some other families exist in the South-West and in
Coastal areas.
Enjoy your time outdoors and remember – if you leave them alone,
they will leave you alone!
©
2015 Jack Glisson of WWW.kentuckyupclose.com