Survival in Tropical Rain Forests

Tropical rain forests cover large but ever shrinking areas in the Americas, Africa and Asia between latitude 25° North and 25° South. These forests have greater than 250 centimeters or 100 inches of rain per year, with the rain fairly evenly distributed throughout the year. (By comparison, deserts have less than 25 centimeters or 10 inches of rain per year.) The dominant organisms are trees of heights up to 90 meters (300 feet) with several layers of vegetation underneath. Each layer may contain its own variety of plant and animal life, and is the reason for the large number of organisms present. The terrain under the blanket of vegetation may be a flat river valley or high mountains, and often it is a combination of the two. The vegetation remains constant throughout the year, and vines and creepers make travel very difficult. Mangrove and palm swamps, bamboo groves, and savanna may also be present, making travel and navigation even more hazardous. But survival in rain forests is probably easier than it is in deserts, mountains, the arctic, or at sea.

The principle hazards to humans in the rain forests are insects and rain. Motion pictures portray rain forests as having lots of large animals such as tigers and jaguar, crocodiles and various venomous snakes. While these may, indeed, be present, they represent a very small danger when compared with the flies, mosquitoes, ticks, leeches, fleas, ants, and centipedes. Also present are many irritating plants which may cause allergic dermatitis or painful puncture wounds. Nettles, rattan, thorns and bayonet grass may penetrate clothing and injure skin and eyes. Scratches, abrasions, lacerations and macerated skin can become infected by bacteria, fungi, and other parasites.

Heat-related illnesses are common although not usually as severe as in the desert. The temperature on the forest floor seldom exceeds 41° C (105° F), while desert temperatures often reach 50° (120°F). But the high humidity in rain forests can make sweating ineffective and precautions should be taken to avoid heat stroke and heat exhaustion. Prickly heat, chafing from wet clothing and warm water and immersion foot are quite common, but usually not life threatening. These may lead to cutaneous fungal infections that are quite difficult to irradicate.

Preparing yourself for trips into rain forests

The best preparation for hiking, bird watching, canoeing and other activities in a rain forest is to get your body and mind in good condition. Walking on trails can be quite strenuous depending on the gradient and density of the vegetation. Aerobic conditioning is a must. Upper body strength is especially valuable in the rare situations in which you become lost and must hack your way through undergrowth or climb over tree roots.

Becoming acclimatized to the heat and humidity will take several days at a minimum and, optimally, two to three weeks. Before setting off on a long trip, take short hikes to accustom yourself to the noises, the insects, plants and difficult footing. Swimming is an invaluable survival skill and can save your life. Read as much about the area and memorize key terrain features from maps or charts. Know the common hazardous plants and animals and learn to identify them from field guides or have local residents point them out to you.

Learning about indigenous peoples, including a few words of their language and their customs is very important. This gives you a better appreciation for the area and helps establish good relations with the people who may have your survival in their hands. File an itinerary with a trustworthy person so rescuers will know where to begin looking for you if you do not return on time.

Clothing

Necessities include long sleeves and long pants made from ripstop cotton, wide brim hat, mosquito head net and gloves. The tropical weight military issue trousers and jacket are ideal and are available in various colors and sizes. The trousers have drawstrings on the legs to limit insect access and have large cargo pockets which are invaluable to any wilderness traveler. The hat keeps off rain, sun and some insects while the gloves protect the hands from rattan, thorns and blisters. The mosquito headnet can be kept folded and stored in a pocket when not needed. Ankle high boots of synthetic nylon or goretex and polypropylene or wool/polypropylene blend socks (at least two pairs) are good foot protection. All clothing should be impregnated with insect repellent

High boots will help support the ankles and prevent the boots from being pulled off in mud. Military jungle boots are high enough to tuck the pants legs in and have drain holes to allow water to drain. But such boots are heavy and not comfortable to walk in. Shoestrings should be made from parachute cord to prevent rot in the dampness. Change socks whenever you stop. This also gives you a chance to check for leeches and ticks. Air dry your feet and apply antifungal powder. Tie the pair of socks that you remove from your feet to the outside of your pack. At the next stop switch socks so that relatively dry socks are constantly worn. (Obviously this system does not work in the rain.)

A goretex rain parka and trousers will keep off the rain but can be quite hot and may cause enough sweating to make you as wet as the rain would. A poncho is more versatile and may allow more air to circulate, but generally is quite warm also. Carry a plastic bag or two to store extra clothing. Most seasoned rain forest travelers do not wear underwear as it does not dry as quickly as the outerwear and may cause chaffing and "jungle rot" or tinea cruris.

Survival kit

Carry quality, multipurpose first aid items, emergency shelter, tools, signal equipment, water, food, and navigational items. The kit should be large enough to be complete yet small enough so that it can be on your person at all times. Obviously, carry the kit in a waterproof container or pack. Before each trip replace items used or damaged. Some of these items can be carried in the pockets of the trousers or jacket. Here is a basic list:

• pocketknife, Swiss Army type with lots of blades
• canteen, 5 liters (5 quarts) collapsible
• iodine crystals, for water purification and cuts
• parachute cord, 15 meters (50 feet)
• mosquito netting
• compass
• whistle
• insect repellent
• bandaids
• waterproof matchbox
• signal mirror
• sunscreen
• penlight
• plastic bags
• map
• safety pins
• fish hooks & line
• candy/peanut butter
• needles and thread
• duct tape
• aluminum foil (.3 square meters (3 sq ft)

All of these items fit in a relatively small container that can be carried on the belt along with the rain gear. Expedition travel through remote areas necessitates carrying a much larger kit that would contain as a minimum a jungle hammock, gill net, machete with sharpening stone and file, extensive first aid kit, extra clothing and boots, signal radio or ELT (emergency locator transmitter), flares, food and cooking utensils. A 35mm aluminum film can hold antimalarial tablets, antibiotics, and a few analgesic tablets. Use cotton to seal the top to absorb moisture.

Survival Situations

Administering first aid and getting to safety are the first priorities in survival situations. Falling down a hillside or out of a canoe may be your introduction to rain forest survival. If you are in a plane or vehicle that may explode or catch fire, move away until you are sure it is safe. Basic first aid or medical care to the level of expertise and equipment available should be administered. If there are no immediate life threats, stop and take time to survey the situation. Make note of your assets, orient your map, inventory your equipment, do whatever you can to avoid panic. Panic can turn a relatively stable situation into a fatal one.

Shelter from insects and rain is your top priority. Protect all exposed skin with insect repellent and put on your mosquito head net. A lean-to type shelter can be made with a poncho and a length of parachute cord. If a vehicle such as a plane or automobile is available, use it for shelter. It also may be a good source of tools and equipment if you use your imagination and improvise. A lean-to made by leaning palm fronds against a fallen tree may be enough to protect you temporarily. If possible construct a sleeping area off of the ground to protect yourself from crawling insects. This along with overhead protection from the rain and your mosquito netting will usually suffice as shelter.

Water is readily available if you know where to look. Obviously rivers, streams, and lakes have water, but it must be purified either with iodine or by boiling. Many jungle plants contain potable water. For example jungle lianas or vines contain large amounts of water that can be obtained by first making a cut through the vine as high up as you can reach, then a cut as low as possible. The water will then flow from the top cut out the bottom cut and can be collected in a container or can be drunk directly from the vine. Many plants collect rain water, and bromeliads and bamboo will still have water trapped in them during dry periods. Do not drink milky or bitter plant fluid. Many formerly cultivated areas contain coconut palms that are excellent sources of fluid and nutrition, and the main exception to the "milky fluid" rule.

There are a variety of plant foods available; banana, bamboo, cashew, taro, coconut, nipa, ferns, rattan, pili nut, mangoes, papaya, breadfruit and guavas. Learning to identify and preparing these plants beforehand will be time well spent. These plants can be a great supplement to a routine expedition diet.

All rain forest animals are edible, but catching a monkey or wild pig, or knowing what to do with a crocodile when you catch one can be a problem. Chances are that you will not have a shot gun or rifle, so go after the slower, less dangerous animals such as grubs, lizards, snakes and fish. Cook all animal food thoroughly to destroy parasites. After skinning and gutting fish or lizards, wrap the meat in aluminum foil or leaves along with a few vegetables and bake in hot coals. Insect grubs and termite larvae can be found in rotten logs and can be eaten raw, although they are better cooked.

Traveling through the rain forest can be extremely difficult and physically exhausting. Before setting out, rest, drink plenty of water, and eat what is available. A compass is mandatory for navigation. Often the sun and stars cannot be seen to give directions. If you do not have a map, hopefully you have memorized key terrain features such as roads, rivers, and villages when you were planning your trip.

Trails and rivers make traveling easier than trying to move through dense underbrush where a distance of 100 yard can take hours. Avoid, if possible, areas along rivers where vegetation is the thickest and avoid high ridges, swamps and rattan; travel in these areas will tire you out very quickly. Go slow. Push aside vegetation with a stick or cut it with a machete. Make frequent stops to check for attached insects and replenish lost fluids. Following game trails to rivers and then traveling down rivers by bamboo raft may be the best solution. Rivers often have villages along them and rivers have an abundance of fish for food. Rivers also contain crocodiles, piranha, other dangerous fish and rapids and waterfalls, so care must be taken.

Because of the thick canopy, signaling to rescuers is often a problem. Downed aircraft, for example, are not easily seen from the air. Smoke from flares or smudge fires may not penetrate the vegetation. A whistle or gunshot, although somewhat muffled by the vegetation, can be heard a greater distance than a shout, but often appear non-directional.

Moving to a clearing will enhance your chances of being seen from the air, but natural clearings are difficult to locate from the ground. Clearing give a view of the sky and may serve as a landing zone for helicopters and starting points for rescue teams. For these reasons travel may be the only option in a survival situation as opposed to remaining where you are in the desert or arctic. Shining a signal mirror in the direction of aircraft sounds or toward the horizon may attract search and rescue teams. Smoke from signal fires or flares may be used when aircraft are moving toward your position and a flashlight can be used at night if a search craft is sighted.

Mel is the Director of the Division of Toxicology and Professor of Emergency Medicine and Pediatrics at the University of Cincinnati, College of Medicine in Cincinnati Ohio, USA. He is a past president of the Wilderness Medical Society.