Is There Really a Jungle Out There?

R. Philip Bouchard
The Philipendium

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You have undoubtedly heard the expression “It’s a jungle out there!” This phrase is intended to convey the difficulty of modern life, by comparing the world of human interactions to a jungle. The implication is that people are often as ruthless as the dangerous animals that we imagine we would encounter in a real jungle. But this raises the question “What is a jungle?” Do jungles actually exist? If so, then what are the defining characteristics of a jungle? In other words, what distinguishes a jungle from a place that isn’t a jungle?

To obtain some answers, we might look for a scientific definition of the word “jungle”. As a general rule, we expect science to provide us with a precise meaning for any term that deals with nature. For example, science has given us precise definitions for the words “fish” and “fruit” — two words with long histories that predate their use as scientific terms. The ancient, popular meanings of these words don’t exactly match up with the scientific usage. Therefore words such as these have dual lives, existing simultaneously as scientific terms and as popular words with fuzzier meanings.

As it turns out, there is no scientific definition for the word “jungle”, because it is not a word that scientists currently use. The closest scientific terms are probably “tropical forest” and “tropical rainforest”. Therefore, to define the word “jungle”, we must look to other sources.

One online dictionary defines jungle as “an area of land overgrown with dense forest and tangled vegetation, typically in the tropics”. This definition is quite consistent with the stereotype so often portrayed in movies, and therefore it closely matches the popular image of a jungle. But do places such as this really exist, or are they a concoction of the imagination?

The problem is that the above definition contains two ideas that are in conflict:

Idea #1: a “dense forest”, which suggests a heavy canopy of leaves, resulting in deep shade

Idea #2: a tangle of dense undergrowth, including vines, leafy plants, and other vegetation

These two features tend not to exist in the same place at the same time, because a thick layer of leafy undergrowth needs a lot of light to survive, and a dense forest canopy prevents that from occurring. If you go for a walk in a forest with a dense canopy anywhere in the world — not just in the tropics — then there is usually very little undergrowth. In fact, if the ground is relatively flat and not too soggy, then it often quite easy to walk through a deep, shady forest — no machete required!

In contrast, there are plenty of places in the world — not just in the tropics — where the low vegetation is so dense that it is difficult or impossible to pass through. In these places, the thick vegetation is not growing in deep shade. For example, in the coastal areas of the southeastern U.S., it can be difficult to pass through a dense understory of saw palmettos — but these are typically found growing under the open canopy of a pine forest, where the palmettos can receive adequate light. In California, some areas of chaparral (shrub lands) are extremely dense — where even a machete would not be of much help — but these plants grow in full sun.

In areas of the world dominated by tropical forest, it is indeed possible to find patches of dense, low vegetation. These patches tend to occur for three distinct reasons:

1) In locations where the forest has been cut down and has begun to regrow, there is no dense canopy of trees to provide a deep shade. Therefore a great deal of growth can occur close to the ground — and this growth can be quite difficult to walk through.

2) Where a river cuts through a shady forest, plenty of light can reach the ground next to the river. This allows dense vegetation to grow along the river banks, producing a continuous wall of greenery from the ground to the canopy. But if you climb the river banks and push 20 steps into the forest, you’ll soon be in deep shade, and the undergrowth mostly disappears.

3) In an undisturbed, mature rainforest, sometimes a large old tree will come crashing down. This opens up a temporary gap in the canopy, allowing light to reach the forest floor. This sets off a mad competition, as all sorts of vegetation sprout and grow in the opening. But eventually the gap in the canopy is plugged by new growth, and the undergrowth disappears.

If you should ever see a photo that purports to show a jungle — illustrating a tangle of dense, low vegetation — then you have an opportunity to do some detective work. Where is all the light coming from? In many cases, part of the tree canopy is visible in the photo, and perhaps you can see large gaps in the canopy. In that case you are probably looking at a location that is growing back from having been cleared, and the canopy has not yet had time to mature and close up. Or perhaps the photo was taken from a boat, illustrating the dense vegetation along the river banks. Another strong possibility is that the photographer was standing at a transition between cleared lands and natural forest — perhaps along a highway, or at the edge of an agricultural field. The edge of the forest will support a dense understory, but a dozen or so steps into the forest the understory should largely disappear.

The upshot is that our most popular concept of a jungle — a dense, continuous canopy of tropical wet forest coexisting with a dense, continuous understory of tangled vegetation — does not actually exist in the real world. However, this is not the only popular image for the word “jungle”, so let’s examine another one. People often say that “lions live in the jungle”. In fact, the lion is often called “the king of the jungle”. The underlying logic sometimes goes like this: “Africa has jungle. Lions live in Africa. Therefore, lions live in the jungle.” This chain of inference overlooks two important details:

1. Africa consists of a wide variety of habitats, ranging from deserts (such as the Sahara and the Kalahari) to tropical rainforest. The continent also includes very large areas of grasslands and savanna (grasslands with scattered trees).

2. Nearly all of the popular nature films shot in Africa, including most of the films that feature lions, present a landscape consisting of grasslands or savanna — not dense, shady forest. Likewise, many other stars of African nature films, such as zebras and gazelles, live in the grasslands.

Therefore, if the lion is indeed the king of the jungle, then the word “jungle” must refer to the African grasslands. An alternative explanation is that a jungle is any wild place where large carnivorous animals roam about. After all, when we say “It’s a jungle out there”, we are implying a dangerous place, rather than a grassy place.

Although most nature films that feature African wildlife are set in the grasslands and savannas of that continent, this does not mean that the African rainforest is devoid of animals. However, filming wildlife in the rainforest is a completely different challenge — and much more difficult. In the grasslands, the fauna is dominated by large herds of herbivores that walk around on the ground eating grass — such as zebras, gazelles, and wildebeest (gnus). Carnivores such as lions, cheetahs, and crocodiles hunt these herbivores. To make a nature film, you can follow the animals around in your 4-wheel-drive vehicle.

But the African rainforest — which is located in the center of the continent, encompassing the basin of the Congo River — is completely different. You don’t find many large herbivores walking around on the forest floor, and certainly not in large herds. Instead, most of the life is high up in the trees, where most of the leaves grow. The herbivores live primarily in the treetops, and the carnivores follow them. Therefore animal life in the rainforest is dominated by creatures that can either climb or fly — birds, monkeys, insects, bats, snakes, and so on. Filming these creatures can be notoriously difficult — because you need to send the film crew high into the canopies of trees, where humans are not so adept at either hiding or pursuing the subjects of interest.

Of course, Africa is not the only continent that includes tropical rainforests. The upper Amazon basin in South America contains a very large area of tropical rainforest. In Asia, the countries of Malaysia, Indonesia, and Papua New Guinea are all predominantly tropical rainforest, along with the southern parts of the Philippines. However, if you define the term “tropical rainforest” quite strictly, then it becomes synonymous with “lowland equatorial evergreen rainforest”. Under this narrow definition, Africa’s share of tropical rainforest is found almost entirely in a single country — the Democratic Republic of Congo.

If instead you broaden your focus to include other types of tropical forest, then some interesting distinctions arise. In many places in the tropics, you can find moist, forested areas that are high in the mountains. These areas are much cooler than the lowlands, and support a completely different set of plants and animals. Some of these areas are called “cloud forests” because they are frequently wrapped in fog from the low clouds — but a more general term is “tropical montane forest”. Another type of tropical forest has distinct rainy and dry seasons. This type of forest is called a “monsoon forest” or a “tropical seasonal forest”. A great deal of rain might fall in the rainy season, followed by an annual period of drought. If the dry season is long and severe, then many of the trees will drop their leaves each year, re-growing them when the rains return — in which case you have a “tropical deciduous forest”.

In the tiny country of Costa Rica, in Central America, you can find all three of these categories — with tourist destinations in each one. Depending upon what you want to see, you might head to one type of forest or another. For example, if you have a strong interest in brightly colored tropical frogs, then the lowland rain forest is the place to go. If you want to see quetzal birds, then you should go to the cloud forest — where the weather is much, much cooler. The seasonal wet/dry forest — an endangered ecosystem that has largely been replaced by agriculture — is located in the far northwest of Costa Rica, a region best known for its sunny beaches.

Although we typically associate the word “rainforest” with the tropics, the temperate zones of the world also include scattered areas of rainforest. In the U.S., the best-known example is the Olympic Peninsula in the state of Washington, parts of which receive more than 100 inches of rain a year. If your idea of a jungle is a dense, rainy forest, then you can visit a jungle without leaving the continental U.S.!

Another approach for figuring out what “jungle” means is to look at where the word came from. The vast majority of words in English have either Germanic or Latin origins — but “jungle” has a completely different background. The British picked up the word in India, back when India was part of the British Empire. The original word in Hindi was jangal, which is derived from the Sanskrit word jaṅgala. According to one source, the Sanskrit word could mean “thicket or forest”, but it could also mean “desert”. This seems oddly contradictory — but there is actually a link between these two meanings. The word originally referred to any wild lands where people did not live and grow crops. These lands could be desert, rainforest, or any other area not suitable for an agricultural society. If we think of “jungle” as simply meaning undeveloped, non-agricultural lands, then it makes sense to associate the term with places where wild animals might find a home — such as lions.

In fact, there is one place in the world outside of Africa where wild lions can still be found — and that is in a tiny corner of India. At one time, lions lived not only in vast areas of Africa, but also throughout the Middle East, westward to at least Greece, and eastward all the way across India. But over the millennia, all lions outside of Africa have been exterminated, except for a single population in Gir Forest National Park in the Indian state of Gujarat. (Even in Africa, there are no more lions in the North African states — only in the sub-Saharan countries.) The vegetation in the Gir Forest is not a rainforest — it is a dry, thorny forest. But India too has a diversity of forest types, including tropical rainforest, tropical dry forest, monsoon forest, and montane forest. India also has deserts. All of these lands would have been considered “jungle”, according to the original meaning of the word. Rudyard Kipling’s The Jungle Book, published in 1894 and the inspiration for a long series of Disney movies, is set in India, not Africa.

These days, you might hear someone say that their back yard has become a jungle, meaning that they have gotten behind in their landscape maintenance. But equally often, the term is used to indicate a place where you face danger from other people. So you might say “The company where I work has become a jungle”, suggesting intense and brutal competition. Or you might hear someone say that parts of a city are a jungle, implying that these are dangerous areas where you risk being attacked. In both of these examples, the dangerous beasts are fellow humans, not wild animals. And the locations are urban settings, rather than wild, undeveloped lands. So we have completely turned the word on its head. To escape the dangers of the modern jungle, according to one line of thinking, we should flee the cities and return to nature — to the quiet, peaceful, undeveloped lands of the world.

The one commonality in all these meanings is that a “jungle” is a place that is out of control — and therefore rather scary. Centuries ago, undeveloped lands were considered frightening and dangerous. Most people felt more comfortable in a human-built landscape of villages and farm fields. But today, for many people, the fear-inducing places are the dense cities — where the dangers take human form, either as fierce competitors or as brutal predators. Therefore using the word “jungle” often represents a point of view — indicating the places where you feel the most vulnerable and the least in control of your own fate. If you love an urban lifestyle, then for you a “jungle” probably refers to the untamed lands of the world. But if you love forests and other natural landscapes, then your “jungle” is probably just the opposite — the dense urban centers of the world.

So yes, there really is a jungle out there, and it’s whatever place you most fear to go!

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R. Philip Bouchard
The Philipendium

Writer, educator, and avid student of nature. My new book is “The Stickler’s Guide to Science in the Age of Misinformation”. See more at www.philipbouchard.com.