The third episode of Planet Earth II was on ‘Jungles’.
Earth is the only planet we know of that has life, and jungles contain 50% of all the plants and animals on land, despite covering less than 6% of the Earth’s surface. (Though in Futurama it will apparently be considered a joke in the future for there to be any jungles whatsoever on Earth. On the bright side, there are jungles on Mars).
David Attenborough’s narration compared jungles to the Garden of Eden. There is a lot of light, heat, food and water here. But, as David Attenborough’s narration continued, “Paradise is crowded”. Competition is fierce.
Jungles have the distinction of being able to make their own weather. There are so many trees and so much heat that water vapour comes out of leaves looking like steam, forms clouds which gather over the forest and burst with rain.
Jungles are home to many colourful creatures, with lots of variety. They have evolved in many different ways. Many animals in jungles can camouflage themselves as plants, leaves, moss and tree bark. It’s extraordinary how specific and accurate some have managed to match certain plants. The programme highlighted the leaf-tailed gecko in particular, which has mimicked the patterns of a tree bark and even some of the plants that commonly grow on it.
In Ecuador the swordbill hummingbird, so called because its beak looks very like a sword. It is longer than the beaks of most hummingbirds, so it can reach nectar in flowers which other hummingbirds can’t. This is relatively similar to what Charles Darwin himself noted with finches in the Galapagos islands, how the same species can evolve to have differences, in this case birds with different beaks developed to access different food.
There was a ridiculously cute baby spider monkey swinging from the trees with her arms and tail. She’s certainly keen, but is still learning. She climbs too high and falls, catching herself with her tail on a branch, but she’s now stuck, and a fall from this height would be certain death. Luckily, her dad was watching the whole time, so comes to save her.
Draco lizards are full of surprises. On first glance they look like a fairly ordinary small lizard, but they have hidden attributes, webbed flaps to bring out if needed. One Draco who has claimed a tree for himself brings out a ‘flag’ underneath his chin to warn a rival off. The rival, having a ‘fight or flight’ dilemma, takes the flight option. And ‘flight’ is fairly literal, as he jumps off the tree and brings out ‘wings’ which he uses to glide to another tree. It’s possible dinosaurs evolved into birds via a similar method.
There is a very wide variety of creatures here, though it was jaw-dropping to find that there are DOLPHINS in a Brazilian jungle! Yes, DOLPHINS! It rains so much sometimes the trees become 30 foot underwater. These dolphins swim in the flooded forest among trees, are almost totally blind and use sonar to find fish.
The caiman crocodile is one the top predators, described as “the rulers of these rivers” in the narration. But it’s a well known saying that the hunter can become the hunted, and it is brutally displayed here when the caiman becomes prey for a jaguar. There are horrible crunching sounds as the jaguar uses its powerful bite – the most powerful bite of any cat – to kill the caiman at its vulnerable point, the back of its skull.
The glass frog, so called because some of their internal organs are visible through their skin, is about the size of a fingernail, and is smaller than many insects. Crickets are much bigger and will try to eat the glass frog!
With the glass frogs we see in this programme, various females have laid their eggs on a leaf and the male protects the eggs until they hatch. A wasp comes along and eats some of the tadpoles out of the eggs. The glass frog can’t protect them all, so has to stay with the most vulnerable. But when a wasp has broken into the frogspawn, some of the tadpoles actually manage to wriggle free to the safety of the water below! More wasps come, but the
father frog has a trick. The wasps mistake the pattern on his back for a cluster of eggs, so when they get close he kicks them away! The wasps sting could still kill him, so he has to time it right. This is all an example of an evolutionary arms race, species having to develop new skills and abilities to win the fight for survival.
During the night jungles are still bright and colourful in their own way. Lots of creatures glow in the dark. Fungi can grow in beautiful shapes. Fungi are a much odder kind of beauty than other natural phenomenon, but beautiful nonetheless. Some are luminous, which is to attract insects. A male click beetle is shown mistaking the fungus light for a female click beetle. He looks and can’t find the female there, and by the time he has given up he has picked up spores from the fungi which he will carry around the forest.
Railroad worms, actually a beetle despite the name, have a red glowing head and a yellow glowing body. The yellow is a warning to potential predators that they are poisonous, so it wouldn’t be a good idea to eat it. However when it comes to the railroad worm’s own prey, millipedes, they switch their yellow lights off leaving only their red one on, described by the narration as a “stealth mode”. As millipedes can’t see red they can’t see the railroad worm.
With birds-of-paradise, as with many birds, the male has a more elaborate plumage and fancier tailfeathers. The red bird-of-paradise are high in the trees, and we see two
males compete by performing a dance. A female chooses one, but then doesn’t seem to like the one she picked much either and rejects his advances!
Wilson’s bird-of-paradise do their courtship on the ground. The male is very brightly coloured and has beautiful feathers. He tries to pick a perfect place to display. He wants a spotlight (sunlight getting through the trees) and as bland a background as possible, no distractions from him. He clears away any leaves. When a female arrives he displays his already colourful plumage, but especially for her he shows bright green feathers which most of the time are hidden.
Despite my Futurama reference joke earlier, it is a serious point that jungles are indeed disappearing from Earth, slowly but surely. Some species, like indri can only live in jungles, and their numbers are going down because of the destruction of jungles. Once again it’s the fault of humans, so we have a responsibility to try to conserve jungles.