Big Thicket researchers and volunteers should read this important information about risks associated with field work.
- Iodine Tablets (photo by Charles Wilder)
- We recommend bringing water with you; for people hiking or doing other hard work at least four quarts should be brought each day.
- Because of the likely presence of disease-causing micro-organisms, always boil, filter, or treat your drinking water.
- Don’t drink directly from streams!
Heat and Humidity Risks
- When the body is unable to cool itself by sweating, several heat-induced illnesses such as heat stress or heat exhaustion and the more severe heat stroke can occur, and can result in death.
- Factors Leading to Heat Stress
- High temperature and humidity; direct sun or heat; limited air movement; physical exertion; poor physical condition; some medicines; and inadequate tolerance for heat.
- Symptoms of Heat Exhaustion
- Headaches, dizziness, lightheadedness or fainting.
- Weakness and moist skin.
- Mood changes such as irritability or confusion.
- Upset stomach or vomiting.
- Symptoms of Heat Stroke
- Dry, hot skin with no sweating.
- Mental confusion or losing consciousness.
- Seizures or convulsions.
- Preventing Heat Stress
- Know signs/symptoms of heat-related illnesses; monitor yourself and others.
- Avoid direct sun; rest regularly.
- Drink lots of water; about 1 cup every 15 minutes.
- Wear lightweight, light colored, loose-fitting clothes.
- Avoid alcohol, caffeinated drinks, or heavy meals.
- What to Do for Heat-Related Illness
- Call 911 (or local emergency number) at once.
- While waiting for help to arrive:
- Move the victim to a cool, shaded area.
- Loosen clothing.
- Provide cool drinking water.
- Fan and mist the person with water.
- National Weather Service, Heat: A Major Killer
- Lightning Strike (photo by Charles Wilder)
- If caught in a lightning storm, seek shelter by moving off any ridges or high points quickly.
- Most lightning strikes are on the upper half of mountain slopes.
- It may be hard to follow “conventional wisdom” to stay away from trees, but at least stay away from tall trees.
- Take shelter between smaller trees.
- Take off any metal frame packs, stash metal walking sticks, and remove zippered jackets.
- Many people are injured by the ground charge that radiates across the ground from the strike point.
- Do not stand on large roots from a nearby tree.
- Fold a sleeping bag, jacket, or other insulating material under your feet; keep your boots together and touching, and crouch down.
- Imported red fire ants (Solenopsis wagneri) deliver a painful
sting that produces a red pustule that itches and burns.
- These stings are usually not serious except for the rare instance of serious allergy.
- Fire ant stings should be kept clean to prevent secondary infections, topical applications can help reduce itching and burning that may last for several days.
- Texas has a native fire ant species that is not a pest species.
- Wasps have unbarbed stingers that can be used again and again, bees have barbed stingers which are left in the victim.
Photo courtesy of the USDA Agricultural Research Service.
- Yellow Jackets (photo by Charles Wilder)
- A sting by a wasp is probably the greatest summertime threat to anyone in the backcountry.
- Should a bee or wasp fly near you, slowly raise your arms to protect your face and stand still or move slowly to escape.
- If you are stung and the stinger is still in your skin, carefully scrape it out with a credit card or a piece of cardboard; don't pull it out because you will likely squeeze the venom from its sac into yourself.
- If you have a severe reaction including swelling, breathing difficulties, severe drop in blood pressure and shock, seek a medical help immediately.
- The Common striped scorpion (Centruroides vittatus) has 4 pairs
of legs, two pinchers and a segmented tail ending in a poison gland with a stinger.
- It is found throughout Texas often under rocks, fallen branches, and forest floor litter.
- They feeds on insects, spiders, centipedes and other scorpions and are active mostly at night.
- A scorpion sting is similar to a bee sting, causing pain and local swelling, but is not serious except for rare instances of allergy for which medical attention should be sought.
- Centipedes (Scutigera coleoptera) have poison claws located directly
under their jaws.
- They are long, multi-segmented arthropods that have one pair of legs for each segment.
- Their bite is similar to a bee sting, if allergic reactions occur consult medical care.
- Brown Recluse (Loxosceles reclusa) is so named for it's shy nature,
it tends to hide during the day and is most active at night.
- Brown Recluse (photo by James O. Howell)
- Often called 'the fiddleback' spider because of the design of a violin on it's back between the eyes and the abdomen, the spider's venom causes death and decay of the tissue surrounding the site of the bite
- Be aware that these spiders like to hide in dark, undisturbed places. Shake out shoes first before putting them on. Wear gloves while reaching into places where visibility is not good, especially if you notice a lot of cobwebs.
- A physician should treat bites as soon as possible.
- Black Widow (Latrodectus mactans) spiders are found in protected cavities outdoors, often in portable toilets, abandoned sheds, cellars and other undisturbed places.
- It is the only shiny black spider (males and juveniles may show more color) and has a red hourglass pattern on the underside of it's abdomen.
- The bite feels like a pin prick or may not be felt, there may be slight local swelling and two faint red spots surrounded by local redness at the bite.
- Pain may become intense within one to three hours and may continue up to 48 hours; usually in the abdomen and back, but may also be felt in the muscles, soles of the feet, and eyelids which may become swollen.
- Other symptoms include nausea, profuse perspiration, tremors, labored breathing and speech, and vomiting.
- During this time, a feeble pulse, cold clammy skin, unconsciousness, convulsions and even death may result if the victim does not receive medical attention immediately.
Common Striped Scorpion (photo by Whitney Cranshaw)
Black Widow (photo by Joseph Berger)
Chiggers and Ticks
- Of the major chigger species in Texas, probably only two are annoying to humans.
- One species lives in upland areas, likes fields, grass and weed areas, wild berry patches and forest underbrush.
- The other chigger species prefers moist habitats such as swamps, bogs, rotten logs and stumps.
- However, both species often live in the same general region.
- Commercially available repellents, such as "DEET" are effective against chigger
- They are formulated as liquids, aerosol sprays, solid sticks and ointments.
- Common dusting sulfur, although somewhat messy and odorous, is also a very effective repellent.
- Immediately after exposure to chigger-infested areas, take a hot bath to kill and
remove chigger larvae.
- Then apply an antiseptic solution to any welts that have appeared to kill trapped chiggers and to prevent infection.
- Normally, two to three days pass before the itching stops.
- There are four species of hard ticks found in eastern Texas: Lone Star Tick (Amblyomma
americanum), American Dog Tick (Dermacentor variabilis), Black-legged
(deer) (TickIxodes scapularis), Brown Dog Tick (Rhipicephalus
- Wear light-colored clothing so that crawling ticks can easily be seen and tuck pant legs into boots or socks so ticks do not have access to skin.
- Use insect repellents according to package instructions.
- To reduce the risk of disease transmission, inspect yourself for ticks frequently and
properly remove any attached ticks promptly.
- Use fine-tipped tweezers to grasp the tick at the skin surface.
- If tweezers are not available, use a tissue or paper towel to protect your fingers from possible exposure to the tick's body fluids.
- With a steady motion, gently pull the tick straight out.
- Do not twist, jerk or crush the tick's body. After removal, clean site and hands with soap and water.
Adult Female Lonestar Tick (Photo courtesy of Ticks and Tick-borne Diseases in Texas)
Adult Female American Dog Tick (Photo courtesy of Ticks and Tick-borne Diseases in Texas)
- There are only four species of snakes that you are likely to encounter that are potentially
dangerous in the Preserve.
- Just watch where you step or place your hands, and be extra careful around any area likely to have higher rodent populations.
- When stepping over fallen logs, make sure a snake isn’t using the other side to direct rodents its way where it can strike them!
- Since snakes are communal, don’t just step backwards automatically when you encounter one, look first!
- Venomous snakes hunt at night and cool-off as the temperature drops; therefore, they need to warm themselves in the morning by basking in the sun, so any sunny clearing is suspect.
- Timber or Canebrake rattlers (Crotalus horridus) are stout, dark-tailed
snakes that can be quite variable in pattern and coloration.
- Canebrake Rattlesnake (photo by L.A. Dawson)
- Body colors range from yellow, tan, or brown to even black.
- Patterning is often black, but can be outlined by white, cream or even a crimson tinge.
- The pattern is "V" or "W" shaped lateral marking with a rusty stripe running down the length of its back.
- They occur across a broad range of habitats and have been found associated with swamps and low lying areas to higher arid locations.
- Coral snakes (Micrurus fulvius) are the only venomous snake in
Texas with brightly colored red, yellow, and black bands completely encircling the body.
- Texas scarlet snakes and Louisiana and Mexican milk snakes have similar red, black, yellow coloration patterns, so it is important to notice the order of the colored bands.
- On scarlet and milk snakes, the bands do not completely encircle the body but stop at ground level, under-bellies being uniform in color.
Coral Snake (photo by Luther C. Goldman)
- Cottonmouths or Water moccasins (Agkistrodon piscivorous), do
not have rattles, but they do have small facial pits, although the pits are difficult to
see from a safe distance.
- Blotched, Yellowbelly and Diamondback water snakes are often mistaken for Cottonmouths because their similar appearance, as well as sharing the same aquatic habitat.
- Cottonmouths are significantly less agile than water snakes and often hold their ground and gape open-mouthed in a threat posture.
Western Cottonmouth (photo by Pete Pattavina)
- Copperheads (Agkistrodon contortrix) are venomous and can be
prevalent in wooded areas.
- Copperheads are hard to see; because their pattern and coloration makes it easy for them to blend in with their surroundings.
- They are found in many habitat types and are active day or night.
- They are most often found sitting in a coiled position.
Copperhead (photo by Allen Bridgman)
- Poison ivy (Toxicodendron radicans) can be a climbing or trailing
vine, a shrub or even a small tree.
- The leaf edges can be smooth, toothed or deeply notched; new spring leaves are red, fall leaves are yellow, orange and red. Poison oak, Toxicodendron pubescens, has a leaf consistently more deeply notched, and looking more like an oak leaf.
- The plant produces small, greenish-white clusters of flowers in spring and white, waxy, berry-like fruits in fall.
- Several variations of the old adage 'Leaves of three, beware of thee' proclaim the warning- typical 3-leaf (occasionally 5-leaf) clusters on a single stem identify it.
- All parts of the plant are toxic in all seasons, burning poison ivy is particularly dangerous because the toxin is carried in the smoke and can cause serious respiratory damage if inhaled.
Poison Ivy (top) with Virginia Creeper (bottom) (photo by Charles Wilder
- The best defense against poison ivy is learning to identify the plant and wearing protective
- If bare skin has been exposed to poison ivy, immediately wash the affected area with soap and large amounts of warm water to reduce or eliminate the possible affects.
- If you did not realize that you touched poison ivy, treatment includes keeping the area clean and dry and applying topical applications of hydrocortisone.
- If your clothing has come in contact with poison ivy, carefully remove and wash the clothing in hot water; this is extremely important because the resin can remain on clothing indefinitely and can cause the same reaction as touching the plant.
- Poison sumac (Toxicodendron Vernix) reacts very much like poison
ivy, but it looks very different.
- It is usually found in very wet, wooded areas.
- It can be a tall shrub or small tree, leaves are arranged in pairs of three to six with a single leaf at the terminal end of the stem.
- The whitish green fruits hang from the plant, non-poisonous varieties of sumac have fruits that are red and upright.
- The same procedures should be followed as for poison ivy exposure.
Poison Sumac (photo by Ted Bodner)
Backcountry Safety Guide. Keith Langdon and Heather MacCulloch. 2004. Inventory and Monitoring Branch, Great Smoky Mountains National Park.
Chiggers L-1223. http://insects.tamu.edu/extension/bulletins/L-1223.html. Phillip J. Hamman. Area Extension Entomologist, Texas A&M University System
Heat Index. http://www.crh.noaa.gov/pub/heat.php. NOAA's National Weather Service Weather Forecast Office.
OSHA Quick Card. http://www.osha.gov/Publications/osha3154.html. Occupational Safety & Health Administration. U.S. Department of Labor.
Rattlesnakes. http://www.tsha.utexas.edu/handbook/online/articles/RR/tdr1.html. The Handbook of Texas Online. The University of Texas Libraries at the University of Texas at Austin.
Texas Junior Naturalist. http://www.tpwd.state.tx.us/learning/junior_naturalists/. Texas Parks and Wildlife Department, 4200 Smith School Road, Austin, TX 78744.
Ticks and Tick-borne Diseases in Texas. http://www.ticktexas.org/ticks/index_ticks.htm. Department of State Health Services, Health Services Region 7, Zoonosis Control, 2408 S. 37th St.,Temple, TX 76504.