Danger in the jungle

The rainforest around Rio Maria is not pristine. The area was logged 50 years or more ago. Large birds that once flew above the trees, such as the Scarlet Macaw, are gone, most likely captured by locals. No howler or spider monkeys are left in this jungle, and the collared peccary (javelina) is not found as it once was. These mammals were probably taken for food or the pet trade by people. This region is not protected and is too close to human habitation for most large animals to survive collection or hunting. Still, the small plants and animals are very diverse and the jungle here has much to offer to biophilic (biology loving) visitors.

The ability of the jungle to rebound from logging is a direct consequence of the millennia that these trees and associated plants have interacted with humans. Panama has been inhabited for at least 11,000 years. The indigenous people have a sophisticated culture, that among other things, developed unique and ornate styles of pottery. In this region, called Coclé, the indigenous culture required rotating agriculture which would have been slash and burn. The jungle in the flat parts around Rio Maria has very likely, over thousands of years, been repeatedly been cut (slashed), burned, cropped and after a few years left to return to jungle to recover its fertility.

While the jungle around Rio Maria was missing some components of an extensive, old-growth, tropical rain forest, it still had incredible diversity and beauty. Only in recent history have humans developed the machines and population densities to completely remove jungle from tremendously large areas. There is little hope the diversity will return to the areas of massive deforestation as it does to the small patches that are cleared for a few years by native agriculturists under slash and burn cultivation. We know that very plant and animal diversity could coexist with the traditional native practices, but those days are now gone.

Working in the forest requires caution. Those who work in the jungle say that falling trees and limbs are the greatest danger. If you are unlucky, one will fall and hit you in the head. If you spend much time in the jungle you will hear limbs falling, and the trees in even this re-grown rain forest can be a couple of hundred feet high, so the branches can gain considerable momentum before they strike an unlucky researcher below. Each tree limb plays host to numerous epiphytes. These epiphytes include the orchids and a number of what we commonly see as houseplants in homes in developed countries of temperate climates (for example ferns, spider plants). These plants take advantage of the limbs of the trees to grow higher in the canopy where they can get far more light than they could on the forest floor. The mass of plants on each branch grows to a greater and greater mass. Eventually the weight is too much for some branches to bear and they come crashing down.

The large trees tend to have shallow root systems that are spread across the jungle floor to intercept nutrients that reach the soil there. Tropical jungles generally have very poor soil and organic materials containing nutrients are rapidly degraded and the nutrients they contain scavenged quickly. This is part of the reason for slash and burn agriculture; the vegetation that is cut down and burned provides nutrients for a few years, but the soil is not productive so the fields are abandoned after a few years. Unfortunately, if cropping continues the soil becomes so
unproductive that not even the jungle can return.

The shallow roots are not good at holding up the trees, and this is made up for by the buttresses (broad supportive ribs) that extend away from the base of the trunks. Even with the buttresses, a large tree will fall occasionally. Because it is connected to others by dense vines, not only will it smash the trees directly where it falls, but also the falling trunk will take many smaller trees down with it.

Tarzan movies are not very realistic, but there really are vines that could support a large primate that crisscross the jungle canopy. We tested this as college students in the jungle finding vines on hills that would allow us to swing high into the air.

When a large tree falls and takes others down with it, the light gap that enters the forest will allow new rapidly growing trees to grow up into the canopy. This process is part of what leads to the tremendous tree diversity in the tropics; the light gaps promote species that would not be able to compete in the dense closed canopy of the jungle.

A newly fallen tree also attracts local people scouring the forest for exotic orchids that might have been growing high in the canopy before the tree fell. These plants can bring a hefty price. The orchids are for sale in the local markets and collectors around the world support a legal and illegal orchid trade.

There are other dangers; toxins are common. Some palm trees commonly found near the ground on of the jungle have large poisonous spikes that will cause a nasty allergic response in the impaled hand unlucky enough to grab a trunk to avoid a fall. Large garishly colored caterpillars have poisonous spines. While these caterpillars are not aggressive, inadvertently brushing against one is not advised.

Paraponera ants that crawl on tree trunks are also called bullet ants because a bite from this inch-long ant feels like a bullet and causes pain for 24 hours. Their large mandibles cause what is said to be the most painful insect sting of all; the pain results from a potent neurotoxin. Initiation rights of some indigenous South American people entail repeated bites from these ants. It is difficult to imagine being stung 20 times without screaming, but this is what is reportedly what it takes to be a man in some cultures.

Poisonous snakes are also a concern, but are less common at higher elevations. It is possible that the bushmaster, Lachesis sp., the largest (up to 14 feet long) of the pit vipers, could be encountered up to 4000 feet elevation. The Fer-de-Lance, Bothrops asper, can be found on the ground or juveniles can be found in trees. Tree vipers also known as eyelash vipers, (two species at high elevations), hang from trees. Hog nosed vipers, tropical rattle snakes, and coral snakes all can be found in Panama. All these species are poisonous and bites from some can be fatal. It is always best to watch where you are stepping and move with care when walking in the jungle. This is not sandal country (but the next day we would see the exception) and boots, not flip flops, are advised. The dry season we were in, is also the time when the bushmasters are most likely to bask near Rio Maria, so we were particularly careful to watch for these vipers.

Of course, insect-borne diseases are also a concern, as they are in much of the tropics. Diseases found in Panama include malaria, chagas disease, dengue fever, yellow fever, and leishmaniesis. We killed an Assassin Bug in our hotel room, known to be a vector of chagas disease that can be fatal if left untreated. The usual precautions against insect bites and appropriate vaccinations at least decrease the worry. If you see an Assassin Bug in your room in Central America, kill it. These issues are not enough to keep many scientists and ecotourists away. The fabulous diversity and unique area are so attractive, and appropriate precautions minimize the chances of danger .