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WHERE IT ALL BEGINS... Frog Pre-Lab

Frogs begin their lives as tadpoles that are hatched in the water from tiny jelly-covered eggs. The mother frog will lay thousands of eggs at one time. Imagine having thousands of brothers and sisters!

The jelly has an awful taste, which protects the eggs from predators until they are ready to hatch.

Tadpoles are born with gills, just like a fish, so that they can breathe under water. They have a big head and a long tail. They definitely do not look like frogs, yet! Tadpoles have a tough life. It’s a good thing they are fast swimmers to escape the many other creatures that hunt them in the pond. They are a favorite food to fish and water beetles.

Metamorphosis is the change of shape during an animal’s life. During metamorphosis the tadpole will develop back legs first, then front legs. Around 6 weeks of life the mouth starts to widen. Sometime around 10 weeks the froglet’s, as it is now called, eyes start to bulge out and the tail begins to shrink and eventually disappear. When the lungs finish developing the froglet makes it’s way onto the land and, Ta-da! It’s a frog!

Frogs and toads are carnivores, which means that they will eat meat.

Small to medium sized frogs eat insects such as flies, mosquitoes, moths and dragonflies. Larger frogs will eat larger insects like grasshoppers and worms.

Some large frogs will even eat small snakes, mice, baby turtles, and even other smaller frogs!

Most frogs will starve before they eat a dead insect or animal.

Frog’s tongues are attached to the front of their mouths rather than at the back like humans. When a frog catches an insect it throws its sticky tongue out of it’s mouth and wraps it around its prey. The frog’s tongue then snaps back and throws the food down its throat.

Frogs have very good eyesight. They bulge out the sides of their heads in order for the frog to see in nearly all directions.

Frogs also have amazing sense of hearing. You can often tell the difference between a male and female frog by the size of their eardrum, which can be seen behind their eyes. If the eardrum is smaller than the eye, the frog is a female. On males their eardrum is the same size as the eye.

Frogs have very powerful back legs and webbed feet that help them jump great distances, as well as, swim. Frogs even use their legs to dig, or burrow, underground for hibernating. Certain frogs can jump up to 20 times their own body length in a single leap.

Every different species of frog has his or her own look. They come in many colors, patterns and sizes.

Frogs have many predators. Animal predators include birds, fish and reptiles.

Most rainforest frogs have pads of sticky hairs on their fingers and toes, as well as, loose sticky skin on their bellies, that make them great climbers to escape their predators. Many of these frogs live in high trees for safety.

Other frogs are very good at camouflaging themselves so that they blend in with their environment, making it harder for their enemies to find them. A frog can change the colour of its skin depending on its surroundings.

Humans have become a major danger for amphibians of all types. Water pollution is causing many deformities in frogs as well as poisoning them, and loss of habitat through the building of roads and houses. In some countries, frog’s legs are considered a delicacy, which means that people love to eat them! Eew!

FROGS vs. TOADS

Many people don’t know the difference between frogs and toads. They are quite different animals, although they belong to the same animal group.

Frogs:

  • Need to live near water
  • Have smooth, moist skin that makes them look “slimy”.
  • Have a narrow body
  • Have higher, rounder, bulgier eyes
  • Have longer hind legs
  • Take long high jumps
  • Have many predators

Toads:

  • Do not need to live near water to survive
  • Have rough, dry, bumpy skin
  • Have a wider body
  • Have lower, football shaped eyes
  • Have shorter, less powerful hind legs
  • Will run or take small hops rather than jump
  • Do not have many predators. Toad’s skin lets out a bitter taste and smell that burns the eyes and nostrils of its predators, much like a skunk does.

And neither frogs nor toads will give you warts! That is just a myth.

DO ALL FROGS SOUND THE SAME?

No!

Every different species of frog makes it’s own special sound and it is only the male frog that can croak. They have a small sac in their throats that vibrates the air as they slowly let it out.

The sounds that frogs make are not what you’d expect. Did you know that there are frogs that chirp? Others can whistle, croak, ribbit, peep, cluck, bark and grunt.

THE DATING GAME

When male frogs are ready to mate they will ‘call’ out to the female frogs. Each different species of frog has their own special sound and that is the sound that the same species of female frog will answer to. Some frogs are so loud they can be heard a mile away! After they meet, they find a suitable spot to mate and lay their eggs.

The male frog will hug the female from behind and as she lays eggs, usually in the water, the male will fertilize them. After that the eggs are on their own, to survive and become tadpoles. There are a few species of frogs that will look after their babies, but not many.

INTERESTING FACTS

  • Did you know that a group of frogs is called an ‘army’?
    (A group of toads is called a ‘knot’.)
  • Frogs don’t drink water they absorb it through their skin.
  • Frog bones form a ring when the frog is hibernating, just like trees do. Scientists can use these rings to figure out the age of a frog

Northern Leopard Frog

A Canadian frog, eh! The northern leopard frog can be found all over Canada and northern U.S. They are the frogs that are often found in the garden, backyard ponds fields and wet ditches beside the road. These frogs hibernate during the winter and mate in the spring.

Because these frogs were, at one time, so common, the leopard frog could also be found in the science lab at many Canadian schools for, that’s right, dissecting! Yuk! Now they have been designated an endangered species.

Questions:

  1. What surrounds the eggs to protect them from predators?
  2. What two things do tadpoles have that frogs do not ?
  3. What do frogs eat ?
  4. Where is a frogs tongue attached in there mouth?
  5. How can you tell the difference between a male and female frog?
  6. Why are humans dangerous to frogs?
  7. Write the differences between frogs and toads.
  8. How do frogs make sounds ?
  9. How far away can frogs be heard?
  10. What does the word hibernate mean ?and do frogs do this ?