Category Zoology

   Most frogs breed near water, but some do breed in unusual places. Tree frogs, for example, many lay their eggs in water that collects in tree hollows- or even in flowers like the bromeliad flower. The vase like shape of this flower allows water to collect inside, and some tree frogs, who never come down from the tree tops, will lay eggs in that water. The water will also be sufficient for a few tadpoles to develop.

            Some of the larger tree frogs of South America dig holes in the ground that fill up with water for the females to lay eggs in, and tadpoles to develop. Some species attach their eggs to leaves that overhang rivers and ponds, so as to prevent the eggs from being eaten by ground predators. The leaves are folded over and stuck together to form a tube for further protection. When the tadpoles hatch, they drop from the jelly right into the water!

   In cool climates, frogs generally breed in spring. This is because as the weather becomes warmer, water levels will rise in ponds, lakes and streams, and the warmer weather ahead allows the baby frogs or tadpoles to develop faster into adults. in the tropics, frogs generally breed during the rainy season as there will be sufficient water in all the pools and streams that had dried up in summer.

            During a breeding season, the female frog produces around 2000 eggs. It lays its eggs in water because the eggs do not have a hard protective shell like bird or reptile eggs. They are laid in jelly-like masses, and unless they are covered with water, they will dry up and die.

           Like frogs, toads also use camouflage as a form of self defense. The fire bellied toad is a green toad with black spots that blends nicely with the leaves and greenery of its habitat. However, its underside is a bright red and black- and this colouring gives this toad its name. Fire bellied toads secrete toxins from their skin, and they want potential predators to know it. When threatened, they rise up on their front legs and arch their back, and flip themselves over completely to display their fiery bellies. This is a clear warning to predators to keep their distance, or risk being killed!

The common European toad bluffs its way out of dangerous situations. When threatened, it stands on its toes and inflates its body with air making it look larger and more dangerous than it actually is. Toads can also excrete a fluid that acts as a self defense against any predators. That excretion may be foul tasting, or have a very mild toxicity. 

Frogs live in swamps, forests, and other places. These places are filled with the prey they need as food. More notably, these places also abound in predators which need frogs as food! Frogs have several enemies- snakes, otters, herons, badgers, hedgehogs and many other animals. Frogs therefore rely on the art of camouflage to avoid getting spotted by their enemies. Some blend with their backgrounds, while others even change colours to match their backgrounds!

The aim of camouflage is to break up the typical frog shape, so that the frog cannot be distinguished from its surroundings. That is why, very often, frogs are a mixture of browns and greens that make it difficult for a predator to determine where the frog ends, and the surroundings begin!

 Tree frogs are usually light green so as to blend in with the leaves, while a tree frog from Brazil looks like a splash of bird droppings on a stone! The Asian horned toad’s colour matches that of the dried leaves and leaf litter on the forest floor, while it is practically impossible to see an African square marked toad if it remains perfectly still against a tree bark! In short, camouflage is important to a frog as it allows the amphibian to melt into the background and become practically invisible when danger approaches. 

      The legs and feet of frogs are adapted to where they live. We know that there are ground-dwelling frogs, aquatic frogs, arboreal frogs or those that live in trees, and burrowing frogs. In each case, the structure of their legs and feet vary greatly.

The legs of ground-dwelling frogs are designed for jumping. The three core bones of the hind leg are fused into a single, strong bone, and the limbs are elongated allowing the frog to apply force to the ground longer.

Burrowing frogs have short, muscular hind legs that they use primarily for digging. They also have a special hardened plate on each foot that they use like a Shovel to dig through soil. Tree frogs have sticky pads on the tips of their fingers and toes that help them grip tree trunks and branches. Some tree-dwelling frogs have specialized webbing between their toes that they used for gliding. Aquatic frogs have webbing too, which makes their swimming easier. 

Frogs generally jump or hop to move about. ‘Rocket frogs’ are so called because of how fast and far they can jump. The black-spotted tree frog is only 3.4 centimetres long, but can jump a staggering 1.5 metres! However, some frogs like walking frogs, get around only by walking slowly. And narrow-mouthed toads creep and crawl to their destinations. Frogs and toads have only five to ten vertebrae and almost no neck. Their front and back are fused together, and so are the two bones in their ankles. This helps them to leap, as it reduces the stress on the bones.

 Some frogs have webbing between digits to aid swimming. And the flying frog can actually glide from tree to tree with its modified webbing. Tree frogs have sticky, sucker-like discs on their hands and feet that help them to climb, and to cling on to vegetation.

Generally speaking, frogs move better in water than on land. A few burrowing species have short hind legs and cannot hop, but all other frogs have long, powerful hind legs, which they use for jumping. Did you know that many frogs can leap 20 times their body length on a level surface?