Amphibians

It’s getting dark, and Michael and Leon are setting up camp for the night. All of a sudden, they hear a strange sound coming from the reeds in the lake, and it’s getting louder and louder. What’s making that sound? Michael and Leon decide to investigate, and they move closer to the reeds. It’s frogs shouting to communicate with other frogs!

Frogs are incredibly interesting animals. Their life starts in water, in a large clump of eggs, left underwater by a female frog. After a few weeks, the eggs are ready to hatch, and tiny tadpoles, or frog larvae, break free. To start with, tadpoles look a lot more like fish than frogs, because they have a long tail and breathe through gills. But slowly, they grow.

First their back limbs form and then their front limbs. Then, the gills get covered with skin, and the tail disappears. This process of change, called metamorphosis, can take several months. At the end of it, the frogs become adults - they have four limbs, no tail, and can live on land. Frogs are not the only animals with this kind of life cycle.

Toads, salamanders and newts, develop the same way! All these animals belong to the group, or class, AMPHIBIANS. Let’s see what else they have in common! The basic characteristic of amphibians is their ability to live both in water and on land. None of them can regulate their temperature - they rely on their environment to help them keep warm or cool enough to survive.

We say they are COLD-BLOODED animals. Adult amphibians use lungs to breathe, but they can’t get enough oxygen just from that type of breathing. So, they breathe through their skin as well! This feature also allows them to breathe underwater. Their skin is bare, has no scales nor hair, but is very moist.

To keep it moist, amphibians need to live in humid environments. That’s why many of them live in tropical rainforests. There are many other animals that live there as well, and some of them might want to eat amphibians. Look at this poison dart frog, for example, it’s no bigger than a coin. It could be an easy meal for other animals.

But it has a secret weapon! It is one of the most poisonous animals on Earth. And its brightly coloured skin tells any potential predators that they should stay away. But amphibians aren’t just food for other animals. Most adult amphibians are actually good hunters themselves.

They eat other, smaller animals, such as insects. Some amphibians, like this toad, have very long, sticky tongues which can be used to catch insects. But being poisonous and good at hunting doesn’t help amphibians when it comes to dealing with changes in their environment. The characteristics of their skin allow amphibians to live in water and on land, but also make them very vulnerable to environmental changes. Amphibians are very sensitive to changes in weather.

Too much sun, or too little rain, can cause their skin to dry out, and their bodies to get dehydrated, which can be life-threatening. Amphibians can also absorb chemicals through their skin, so they are often the first group of animals to be affected by pollution. There is a high chance that many amphibians will die, and entire species might become extinct. We must take care of the environment, and make sure we don’t pollute it. This way we can protect habitats where amphibians live - just like the lake where Michael and Leon are camping.