Crestone Eagle, April 2006:
Serpentine wild neighbors (Part 3
part 3 of our look at small wildlife in the Crestone area
we will examine snakes. We do not have many snakes in the
Crestone area, the main reason being that our elevation averages
8,000’, with most snakes preferring to live below 6,000’.
There are many rattlers on the west side of the Valley and
further south along the Sangres.
Most Colorado snakes are nonvenomous (i.e. nonpoisonous),
harmless and beneficial to people. It should also be noted
that nonvenomous and venomous species can be easily distinguished
from each other.
Humans have coped with snakes for centuries, yet the ancestors
of snakes appeared long before our own predecessors. Their
roots date back to the Triassic period, approximately 190
million years ago. Snakes possess the following reptilian
characteristics: they have scales, are ectothermic (they rely
on external sources to control their body temperature), and,
like most reptiles, most of them lay eggs.
Most snakes prey predominantly on rodents, ground squirrels
or rabbits, although some also eat bird eggs, nestlings, lizards,
and insects. They, in turn, are prey for eagles, hawks, foxes,
coyotes, skunks, raccoons, badgers and humans. Domestic cats
will go after them, too. Pigs, chickens, sheep and horses
have been known to kill snakes, especially in areas with venomous
snakes, but this is more a result of instinctive fear rather
than true predation.
Colorado has 25 species of snakes, the western rattlesnake
(aka prairie rattlesnake—Crotalus viridis)
and the Massasauga rattlesnake—(Sistrurus catenatus)
are the only venomous species in the state (in the United
States there are only a total of four venomous snakes—coralsnake,
copperhead, cottonmouth water moccasin and rattlesnake).
The western rattlesnake appears in most habitats throughout
Colorado. The Massasauga however, is limited to the southeastern
grasslands and is not found in our area. There are six basic
ways to distinguish these two venomous snakes from their nonvenomous
relatives: 1) rattles at the end of the tail; 2) fangs in
addition to their rows of teeth; 3) facial pits between the
nostrils and eyes; 4) vertical and elliptical pupils that
may look like thin lines in bright light (nonvenomous snakes
have round pupils); 5) a single row of scales between the
vent and the tip of the tail. (nonvenomous snakes have two
rows of scales); 6) broad triangular head and narrow neck.
There are only two kinds of snakes in the Crestone area,
bull snakes and garter snakes. Rattlesnakes live in our county,
along with 14 other kinds of snakes in neighboring counties.
We will only look at the three that call Saguache County their
Perhaps the main reason there have never been any rattlesnakes
reported in Crestone is because they prefer to live below
7500’ feet. They are nearby, for the most part, west
of Highway 17 and south of the Great Sand Dunes.
Rattlesnakes are poisonous snakes and all rattlesnakes possess
a rattle at the end of their tail. Like all snakes, rattlers
are cold-blooded, which means they are the same temperature
as the environment. The length of an adult western rattlesnake
averages 4 1/2 feet, maximum length 6 1/2 feet. They continue
to grow all their lives, getting bigger each year. They are
usually a lighter gray or brown color with darker, rounded
or diamond shaped patterns that are edged in a contrasting
color. They also have a light stripe from their eye to the
corners of their mouths. They have two rows of similar, but
smaller blotches on their sides, with a wide head, narrow
neck, and stout body.
Rattlesnakes are carnivores (meat-eaters). They mostly hunt
at night. They are nocturnal and can sense the heat of their
potential prey. Rattlers kill prey with venom, which also
contains digestive enzymes that begin to dissolve the meat
even before the snake eats it. Like all snakes, they swallow
prey whole, head first.
In all of Colorado, rattlesnakes spend the winter hibernating
in a lair with many other rattlers. These spots are known
as snake dens. Mating occurs in the spring. Most snakes lay
eggs, but with rattlesnakes eggs are retained in the mother’s
body until hatched, with the young being born live. The female
rattler may contain from 4 to 25 eggs, from which an average
of 9 or 10 hardy young are born live. They will give birth
in the autumn, with each baby being 10 inches or more in length.
Young rattlers are completely independent of the mother.
They only remain in the area of their birth for the first
7 to 10 days, until they shed their baby skin and add their
first rattle. The litter will then disperse and begin the
search for food. Many newborns do not survive the first year,
either dying of hunger or being eaten by birds and other animals.
Many will perish during the first winter, if they can’t
find a suitable warm den in which to hibernate.
According to the Colorado Division of Wildlife, it is legal
to kill rattlesnakes only when necessary to protect life or
property. The most common method to kill a rattlesnake is
clubbing or shooting. The western rattlesnake and all nonpoisonous
snakes are classified as non game wildlife and are protected
by state law, except as noted above.
Rattlers try to avoid humans. If bitten by a rattlesnake,
remain as calm as possible. They do not always release venom
when they bite. If venom is present, panic will only increase
your heart rate, which will cause the poison to circulate
more quickly throughout your body. Do not try to kill the
snake because it may lead to additional bites and delay your
arrival at the hospital for treatment. There is antivenin
available for use against all native pit vipers in the United
States, so it is no longer imperative to determine the species
of rattlesnake. The most useful snakebite first aid kit is
car keys and a phone for calling the hospital. If possible,
have another person drive and call ahead to the hospital to
let them know you are on the way. One final note, all of the
other treatments for treating snake bites (like suckling out
the poison with your mouth)—forget about them—get
to the hospital, the sooner the better!
There is a very slight difference between bull snakes (Pituophis
catenifer sayi) and gopher snakes (Pituophis catenifer
deserticola), and what we have living in Crestone are
called bull snakes, which are closely related to pine snakes
(Pituophis melanoleucuss). The bull snake is a hissing
constrictor—a snake that kills by squeezing prey until
the victim can no longer breathe.
Members of the Colubridae family, the large bull
snake is usually between 36” and 80” long, with
some as long as 110”. They range in color from green-gray
to tan to cream-yellow, with large black, brown or reddish
blotches on their back and smaller ones along their sides.
Most have a dark line between the eyes and another from behind
the eyes to the angle of the jaw. Sometimes striped individuals,
with or without blotches, are found. They have a moderately
stout body, with keeled scales.
This snake is most active during the day. They eat every
10 days. Bull snakes are good tree climbers, and they will
search for prey in burrows, dens and rocks. When alarmed,
they coil into an S-shape, hiss loudly and rapidly vibrate
their tails on the ground, mimicking the warning of the similar-looking
rattlesnake. Because of this action, people sometimes mistake
them for rattlesnakes. In the winter, bull snakes hibernate,
retreating to communal dens, sometimes sharing the lair with
In the breeding season, males vigorously defend their territories
against all competing males. Six weeks after mating, the female
will lay a clutch of eggs with 2—24 eggs each. The eggs
incubate for about 70 days depending on temperatures, and
hatchlings emerge fully developed within 10 weeks and are
12-18 inches in length, large enough to eat small mice. Bull
snakes in the wild reach maturity in 3-4 years. Their total
life span is around 12 years in the wild, but in captivity
they can live 20+ years.
Their range in our state is usually below 8500’, so
you’re more likely to see them out in the Grants than
in our mountains.
Often miscalled garden or gardener snakes, garter snakes (aka
water snake—Thamnophis spp—meaning bush
snake) are found all over Colorado, including here in
Crestone, where the western terrestrial garter snake (Thamnophis
elegans) lives. Garter snakes are one of the most common
of snakes, having the northernmost range of all North American
snakes, they can be found from the Yukon down to Costa Rica,
and from the Pacific to the Atlantic coasts. They are the
most likely snake to be found in Crestone.
Garter snakes rarely exceed three feet in length and remain
a slender two inches in girth. There are fifteen species in
the United States, with ten species (plus subspecies) occurring
in the western U.S. In Colorado, they are found up to 11,000’,
but have been found at over 13,000’ in some areas. Depending
upon their species, they live from 3-10 years. Due to their
small size, garters heat up and cool down quickly. Like most
reptiles, they warm up by basking in the sun. They strive
to maintain their body temperature between 72° and 88°
The garters here in Crestone are generally brown to gray
or gray and light tan checkerboard pattern in juveniles, which
darkens and becomes obscure with age. A light stripe down
sides of body also becomes less prominent with age. They are
quite agile, a trait which also enables them to successfully
capture prey. They encounter their prey while moving through
their territory during the cooler parts of the day—early
morning, late afternoon and early evening. Garter diets range
from birds to mammals. Large prey may be pushed against a
rock to anchor it in place while the snake works its jaws
around it. They rarely constrict their prey, instead stunning
or killing it before eating.
Garters living in Crestone must hibernate during the winter
due to the cold and reduced number of hours available for
sunlight basking. They will stock up on body fat by feeding
heavily during the late summer. They hibernate in aggregations—hundreds
of snakes might gather in the same location, spending the
winter together and then being accessible to each other for
spring breeding. Males, upon emerging from hibernation, become
sexually active, ensuring that females will be mated at the
time they leave the den. Their young are born in the late
summer. The litter size is from 10-30, with some litters recorded
as much as 60-85 offspring. The young’s average size
is 9”. They are independent from birth.
Predators of garters are normally smaller animals, with the
larger carnivores only occasionally catching and eating them—as
they normally don’t bother much with them because of
their small size, which doesn’t make it worth the expenditure
of time and energy necessary to capture them.
A final note on all snakes. They can and do get into our
homes. They come in the same way mice do —through holes
in the foundation. This can be solved by caulking and sealing
all holes. Also, reduce cover and food supplies to discourage
them from living anywhere on your property.
If they do get in, there are two best ways to get rid of
them by either placing a box over the snake and sliding a
piece of cardboard underneath the box or by sweeping the snake
into a large bucket with a broom to release outdoors. You
can also just pick them up gently behind the head, as long
as they are nonpoisonous, which should always be the case
to the Eagle!