|
 Spring
is here, and reptiles, meaning most cold-blooded
animals, become very active when temperatures soar
into the nineties. August and September are
traditionally the most active months for
rattlesnakes on the Sonoran Desert at elevations
below 4,000 feet. But in the spring reptiles come
out of hibernation and begin their search for food.
In late fall when temperatures drop below
seventy-eight degrees reptiles begin to prepare for
hibernation. I have lived in the Sonoran Desert for
the past sixty years and I have encountered hundreds
of rattlesnakes. If the truth were known, most of us
who walk or hike in the desert will pass by ten
snakes for everyone we actually see. Under most
conditions a rattlesnake is very difficult to spot
unless it is disturbed and it moves. Rattlesnakes
generally rattle before they move.
A rattlesnake can easily be identified by the
triangular-shape of its head and the rattle on its
tail. A closer examination will reveal an
elliptical-shaped pupil in its eye. Believe me I
don’t usually get that close to look! This trait is
common to poisonous snakes in the Sonoran Desert.
All rattlesnakes will have a pit organ near the
nostril orifice.
 Rattlesnakes
come in a variety of colors and patterns. Most found
in our area will have rings around their tails above
the rattles. The color of these rings will alternate
between black and white in various shades. The
visibility of these rings will depend on the
species.
The Western Diamond Back rattler’s rings are very
pronounced and stand out, where as the rings on an
Arizona Black is not very visible because of the
blending of the rings. Occasionally a rattlesnake
will lose it rattlers; when this occurs, the
difficulty of identification increases.
Rattlesnakes are ectothermic vertebrates
(cold-blooded animals), meaning they lack an
appropriate physiological mechanism for maintaining
body temperature. All cold-blooded animals are at
the mercy of their environment. Air and ground
temperatures dramatically affects the all reptiles
in their environment. This condition directly
affects their daily rhythm of activity in their
habitat.
There are six species of rattlesnakes in our area.
They include the Western Diamond Back (Crotalus
atrox), Mohave (Crotalus scutulatus), Arizona Black
(Crotalus vidiris), Black-Tailed (Crotalus molossos),
Sidewinder (Crotalus cerastes), and the Tiger
(Crotalus tigris). These animals have a very highly
developed mechanism for injecting venom therefore
making them very successful predators on the desert.
A rattlesnake’s diet is composed of small rodents
82% to 85% of the time.
Reptiles, including rattlesnakes, like cool shady
spots during the spring, summer and fall months.
During the winter months rattlesnakes generally go
underground and hibernate. They usually choose caves
and old mine tunnels. Occasionally dens of
rattlesnakes have been accidentally uncovered by
construction equipment and hundreds of rattlesnakes
are found at one time. Rattlesnakes have been known
to come out of hibernation if temperature warm up to
78 degrees Fahrenheit. The functioning temperature
for a rattlesnake is 72 to 78 degrees Fahrenheit and
its effective temperature is 82 degrees Fahrenheit
to 96 Degrees Fahrenheit. The effective temperature
is the temperature at which the snake moves about
and hunts for prey. Direct exposure to heat or
sunlight will kill a rattlesnake in 10 to 15
minutes.
You might say rattlesnake season is twelve months a
year in the lower Sonoran Desert if temperatures
rise above 72 degrees Fahrenheit in the winter
months. Rattlesnakes are most commonly sighted from
the first of April until about the middle of
October. These animals are primarily nocturnal and
prefer the hours after sundown and before sunrise.
Most victims bitten by rattlesnakes are generally
bitten ½ hour before sundown and up to two hours
after sundown. It is estimated 72% of all bites
occur during this period.
There are some interesting facts about rattlesnakes.
The oldest known rattlesnake in captivity was 30
years and 7 months. This snake was a Western Diamond
Back (Crotalus atrox). The largest rattlesnake
officially recorded was an Eastern Diamond Back
(Crotalus adamatus) at 7 feet 4 inches. The largest
Western Diamondback was measured live at 6 feet 8
inches. There have been many wild claims about ten
to fifteen-foot rattlesnakes, but usually these are
snakes that were measured after death and their skin
had been stretched. The average distance a
rattlesnake can strike and effectively inject venom
is approximately one-third of its body length.
Some eighty per cent of all rattlesnake bites are
the results of carelessness or the handling of
rattlesnakes by older juveniles or young adults. It
is now estimated some twenty per cent of rattlesnake
bites are accidental or legitimate. About fifteen
per cent of rattlesnake bites are dry socket-bites,
meaning no venom was injected into the victim.
The Arizona Poison Control Center and other medical
resources reported some one hundred and twenty-one
Crotalus envenomizations for the year 1991. This
statistics quadrupled in 2003. Again statistics have
almost quadrupled for 2005. These numbers continue
to increase each year as our population continues to
grow and more people head for the outdoors.
How do you know a rattlesnake has actually bitten
you and if the reptile injected venom? There are
several signs and symptoms of envenomization. First
there will be fang marks. These fang marks can be
singular, dual or even a scratch. Fang marks are
generally a very small puncture wound. A burning
sensation usually follows the injection of venom by
the reptile. A metallic or rubbery taste in the
mouth often follows a bite, but not always. The
tingling of the tongue or numbness can also occur.
If a rattlesnake has injected venom into its victim,
local swelling will occur within ten minutes. The
amount of venom injected is generally indicated by
the severity of edema or swelling at fang puncture
site. Nausea and weakness is often associated with
the bite. Black or blue discoloration will generally
appear near the site of the puncture wounds caused
by the fangs after three to six hours. Every snake
bite victim should be treated for shock, a greater
threat to the victim’s survival then the venom.
The following is the recommended first aid for a
rattlesnake bite. Call 911 immediately, snakebite is
a medical emergency. If medical help is several
hours away the following treatment is recommended.
Calm and reassure the victim, decrease the movement
of the limb. Identify the snake if possible without
further risk of another bite. It is not recommended
to use a constricting band or tourniquet unless you
are a medical professional. Many snakebite victims
have come into emergency rooms with a constricting
band, such as shoelace, completely obliterated by
edema or swelling. It is extremely important to move
the victim to a medical facility without delay.
The following are some things we can do to prevent
rattlesnake bite. When walking in the desert or in
any area known for reptile habitation, always look
where you step, or place your foot, or feet (Caution
should always be used at night, late evening, and
early morning). Always look where you are placing
your hands or fingers. Always look before sitting
down, especially around or near boulders or brush.
Think before defecating or urinating in the
outdoors. Small children must be closely supervised
at all times in areas of possible snake infestation
or inhabitation.
If you and your family observe these basic rules you
should be safe from snakebite.
As urbanization continues at the desert edge in
Arizona the threat of snakebite is always a reality.
I have tried to be as thorough as I can with
accurate information about rattlesnakes in Arizona.
It is important to take note, the better
understanding we have of reptiles, the better chance
we have of not becoming a victim.
I would like to thank Jude McNally and his staff,
Arizona Poison Control Center, University of
Arizona, Tucson, Arizona, and Dr. Findlay E. Russell
and his enormously valuable resource Snake Venom
Poisoning printed by Scholium International, Inc.,
Great Neck, New York 11021. This book is a
physician’s desk reference for snake venom
poisoning.
For information call Arizona Poison Control System
1-800-362-0101.For snake removal in Apache Junction
call Apache Junction Fire District at 982-4440
Tom Kollenborn directed the Snake Alert program
for the Apache Junction Unified School District for
17 years. He attended workshops and worked closely
with the University of Arizona Poison Control
Center. |
