It rained overnight, hard, and lots of it. It sounded like the sky opened up on the thatched roofs of our cabins. The rain was hard enough to drown out the racket caused by the millions of tropical insects, frogs and who knows what else. You might think I am exaggerating, but several of our explorers resorted to sleeping with earplugs until the deluge provided some welcome “cover noise”. By morning, the rain had faded to mere dripping from all of the tropical trees. They’ve had a good deal of rain in this area of the Amazon this year, in contrast to the lower river areas where several years of drought is underway. The lodge sits on a lake and is surrounded by small streams and marshes, all of which are high with the extra water.
We set off at 6:30 a.m. in a dugout canoe across the lake to go up one of the small feeder streams. On the way, we sat and watched a family of Squirrel monkeys move through the trees at the edge of the lake. Squirrel monkeys are nomadic groups with a family make-up based on females, similar to our local killer whale pods. They are small (about the size of a small cat) and very agile. They move fast and jump from tree-top down several stories to land on branches. It was the movement of the trees, not seeing the monkeys themselves, that tipped us off to their presence. Their calls, which are the basis of communication, are a series of high-pitched whistles that are almost out of the range of human hearing.
We reached the end of the stream, as far inland from the lake as we could go, and began walking. Because of the heavy rain during the night, the trail was not always dry and the need for rubber boots became immediately apparent. We learned about how most vegetation in the jungle is controlled by nutrients, or the lack of them. There are no bears to drag salmon into the forest and the soils lose most of the water soluble minerals and organic material because of the amount of rain that washes them yearly. Most vegetation depends on the decay of other vegetation, with the resulting recycling of the nutrients, for their own growth. Birds do bring in some nitrogen and phosphorous (essential to plant growth), as do insects. And, there are a few larger mammals, such as pigs – but the density of larger mammals per hectare is much lower than we find in B.C.’s forests.
Some trees are very tall, and grow quickly, reaching up to attract birds, bats and other life in their canopy. They depend on these animals to bring nutrients, such as bird droppings which serve as important fertilizer falling down through the canopy to the trees’ roots. Other plants eek out an existence on scattered nutrients via the forest floor beneath the tall canopy trees. They tend to be much smaller in size and make up an “understory” not unlike what you might find in a B.C. forest. A tropical rain forest is mother nature’s ultimate recycling machine. Most plants have evolved to spreading their roots and soaking up any nutrients that fall to the ground (many of the roots are not even underground, but lying on top of it) from above or from decaying leaves and limbs. Decay is quick because of the temperature, humidity and rain, and nothing is wasted.
The walk was about exploring and learning – not facts as much as a general or viscera understanding of how a tropical rainforest works, what matters to the plants and animals, and their controlling factors. We were hot when we returned to the lodge at 11:30, so it was off to the lake for a swim. The lake does have at least two species of piranha, caimans, and anacondas in it, giving some of our explorers pause. Assured by our guides, everyone hopped in, cooling themselves in a most satisfying way. The lake, while warm by B.C. standards, brought our core body temperatures down a few degrees, a very welcome respite now that the air temperature was approaching 30 degrees with a 95% humidity. Off to lunch, a siesta, and back out at 4 p.m. for more exploring.