· Rattlesnakes are large, venomous snakes that
are found throughout North and South America. The greatest concentration of
them is in the South-western United States and in Northern Mexico. Arizona is
home to 13 species of rattler, more than any other state. The most distinctive
feature that these species share is the rattle.
· Residents of the South-western United States
likely have heard the distinctive buzz of these pit vipers. Their namesake
rattle is a highly effective warning sign, signalling predators to stay away.
“Rattles are segments of keratin that fit loosely inside one another at the end
of the snake’s tail,” explained Sara Viernum, a herpetologist based in Madison, Wisconsin.
“These segments knock against each other to produce a buzzing sound when the
snake holds its tail vertically and vibrates the rattle. Each time a
rattlesnake sheds its skin it adds another segment to the rattle.”
· Scientists consider the rattlesnake’s
rattle a highly evolved and sophisticated warning system — which makes sense since,
according to the San Diego Zoo, these are the newest and most evolved snakes in the world.
·
Rattlesnakes also hiss, a second element of its warning posture
that is often overlooked and overshadowed by its rattle, writes Laurence Monroe
Klauber in "Rattlesnake: Their Habits, Life Histories, and Influence on
Mankind " (University of California Press, 1997). Viernum said the
behavior “is similar to a cat hissing when threatened by a dog. In
rattlesnakes, hissing and rattling their tails both serve as warning signals.
·
“The process of hissing occurs when a snake forcefully expels
air from the glottis within the throat,” Viernum continued. “This causes
structures within the glottis to rattle, creating the hissing sound.” The
snake's one functional lung has relatively large air capacity, and as the snake
hisses, its body may swell up or deflate. Interestingly, snakes are deaf to
airborne sounds, so the hiss is only a warning for animals that can hear and
not a means of communication with other snakes.
·
These adaptable serpents can thrive in a
variety of environments. They are most abundant in the desert sands of the
Southwest, but they also like grasslands, scrub brush and rocky hills. They can
be found in the swamplands of the South-eastern United States and in the
meadows of the Northeast. These snakes can handle high elevation and are found
everywhere from sea level to 11,000 feet (3,353 m), according to the San
Diego Zoo.
·
The National Wildlife Federation reported that rattlesnakes typically
live for 10 to 25 years.
·
Most people bitten by rattlesnakes have inadvertently stepped on
them — so watch where you’re walking! Rattlesnake bites can be dangerous but
are very rarely fatal to humans. With proper medical treatment, including
antivenin, bites are usually not serious.
·
Their venom is extremely potent. “The venom of most rattlesnake
species is composed mainly of hem toxins,” Viernum said. “Symptoms include
temporary and/or permanent tissue and muscle damage, loss of an extremity
depending on the location of the bite, internal bleeding, and extreme pain
around the injection area.”
·
Some rattlesnake species have venom that contains neurotoxins.
“Mojave, tiger, and speckled rattlesnakes are examples of rattlesnakes where
either the entire species or certain populations within the species produce
neurotoxins,” said Viernum. She explained that neurotoxins act faster than hem
toxins and attack the nervous system. “Symptoms from a neurotoxic rattlesnake
bite include problems with vision, difficulty swallowing and speaking, skeletal
muscle weakness, difficulty breathing, and respiratory failure.”
·
Nevertheless, Viernum reinforced the idea that fatalities from
rattlesnake bites are rare if treated in a timely manner.