Venomous Critters of the Southwestern Deserts

ISSN-1059-6518

Venomous Critters of the Southwestern Deserts

By Jeff DeBellis

Illustrations by T.B.R. Walsh

“Those who travel in desert places do indeed meet with creatures surpassing all description.”

–Cormac McCarthy, Blood Meridian

Deserts are generally inhospitable places. They’re either too hot, too cold, too dry, or too windy. Sandstorms, monsoons, and flash floods ravage the land. The plants are spiky and the animals are venomous. Nonetheless, people like to visit the desert. A lot of people. Because despite the downsides, deserts are beautiful.

There are three distinct hot deserts in the American Southwest – the Chihuahuan, the Sonoran, and the Mojave. The Chihuahuan Desert covers southern New Mexico, western Texas, the extreme southeastern corner of Arizona, and extends into the Mexican states of Chihuahua, Coahuila, and Durango. The Sonoran Desert extends from southern Arizona and southeastern California into the Mexican state of Sonora. The Mojave covers southeastern California, southern Nevada, northwestern Arizona, and a tiny corner of southwestern Utah. The boundaries of the three deserts are determined by the distribution of plant and animal species. In some cases, the individual deserts are bounded by mountain ranges that form “sky islands” of more temperate habitat. Hot deserts differ from cold deserts (like the Great Basin farther north) in that most of their precipitation comes in the form of rain, as opposed to snow.

Deserts are home to a startlingly wide variety of plants and animals that have adapted to the harsh conditions. The Chihuahuan Desert is one of the most biodiverse arid regions on Earth. Most desert animals are not actually venomous. Regardless, all wild animals should be appreciated only from a safe distance. The creatures that are venomous include reptiles, such as snakes and Gila monsters, and arachnids, including spiders, scorpions, and to a lesser degree, tarantulas. This article describes many of the venomous species that are native to the region.

REPTILES

Rattlesnakes

Rattlesnakes live nearly everywhere in the United States, but they are especially abundant in the southwest. There are 36 species in the western hemisphere, 17 in the U.S., and 14 in the southwestern deserts. The most poisonous of these are the Mojave rattlesnake (Crotalus scutulatus), with an LD50 SC of 0.31 mg/kg, and the tiger rattlesnake (Crotalus tigris), with an LD50 SC of 0.21 mg/kg. The LD50, also known as the median lethal dose, indicates how much venom it takes for a snake to kill 50% of its prey. The lower the number, the more potent the venom. The “SC” refers to subcutaneous injection, which is the most common way that humans are exposed to the venom. For comparison, the timber rattlesnake of the Eastern United States has an LD50 SC of 2.25 mg/kg.

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YOUR PASSPORT TO INTERNATIONAL TRAVEL HEALTH and SAFETY

Volume 30 Number 1 ISSN:1059-6518

By Frank Hubbell, DO

FACT: 1.1 billion people cross international borders every year!

How many of these international travelers know what is waiting for them at the end of the runway or on the other side of the border? At home you are most likely safe. You have potable drinking water, safe food to eat, reliable power, screens on your windows and doors to protect you from marauding insects, and have excellent, available, immediate health care when needed. To put it simply, most of us live in a bubble. The question is, are you sure that you are prepared for the times when you leave the safety of your bubble?

This is the material that we use in our Travel Clinic to help educate and prepare people for international travel. We offer it here for your review and, if necessary, take with you to a consult for travel medicine.           

TRAVEL PLANS:

Make Out a Trip Itinerary:

When are you going and for how long?

Leaving:

Returning:

Where are you going?

Rural:

Urban:

What are you planning on doing while there?

Travel plans?

How are you planning on getting around?

Previous International Travel History:

When did you go?

Where did you go and for how long?

MEDICAL HISTORY:
Past Medical and Surgical History:

Allergies

Medications – name and dosage

Immune Status – any history of autoimmune diseases, HIV, DM

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Simple Rescue Knots

 

ISSN: 1059-6518

By Paul MacMillan, EMT

Illustrations by T.B.R. Walsh

If you do any research on knots you will find that thousands of knots have been discovered over the years. Many people in different occupations and the trades have favorite knots they use everyday on the job. For example sailors use certain types of knots compared to a weaver or someone who is doing search and rescue work.

If you are the average person you do not use different types of knots all the time. Knot tying is a perishable skill. In other words “if you do not use it you lose it.” On occasions you might need to tie something down or secure something using rope or webbing.

As an average person who does not tie a lot of knots it is important to learn a few basic knots that are easy to remember in case of an emergency. If you learn these few basic knots and you pull out a length of rope from time to time to practice them you will have this skill to use when you need it most.

Basic Rope Information

Remember every rope has a “breaking strength,” which means you put enough tension on the rope it will eventually break. In boating safety they generally consider a safe working load of a rope to be one-fifth of the ropes breaking strength. It is important to note that knots and the age of the rope tend to lower the strength of the rope. Most ropes that you buy in a hardware store have a safe working load of 300 pounds or less.

For example you need to lift injured man using ropes. The man weighs approximately 200 lbs. You have to tie a knot in the rope, and the strength of the knot is rated at 60%. Using this knot it has reduced you safe working load from 300 pounds down to 180 pounds. Now the rope that we are using is now beyond the safe working load to lift this 200 lb. man to safety.

There is very little research out there that clearly defines the strength of different knots. Because there is so little information on knot strength we are going to rely on two professions that use ropes and knot in life and death situations. Emergency services rescue operations and rock climbing. These professions provide us with simple knots that can be used in almost any type of situation.

Basic Terminology for Tying Knots

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Brazilian pepper, Schinus terebinthifolius,

CEP header

ISSN:1059-6518 Volume 29 Number 3

By Brandon Munsell NREMT-P , WEMT-P, SOLO Instructor

As the campfire kicks into high gear, a camper throws on boughs from a nearby tree. Although the tree limbs seem dead, the tree they were taken from is abloom with bright red berries and serrated toothed leaflets. As the now burning branch begins to spew smoke, a wind directs it towards gathered campers. Upon inhalation the members begin to experience irritation to their faces and throats, and they also begin to tear up as they assume tripoding positions to catch their breath. As they retreat from the offending fumes, many begin to wheeze and seek water for their now burning eyes. What has caused this unexpected reaction?

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