Tag Archives: education

Predator, prey, frogs and food chains

Most animals in a habitat can be classified as predators, prey or both. A predator is an animal which kills another animal (the prey) for food. For example, a snake is a predator because it eats frogs (prey). However, the frog is also a predator (however unintimidating it seems!) because it eats grasshoppers. With so many animals having differing diets, even a small environment can produce a food web such as this one.

ImageBecause the grass eats no other species, only consuming nutrients from the soil, we call it a producer. The fox and snake are called top consumers because no other species eats them within this habitat. But in certain habitats, large birds of prey eat snakes.

Food webs can be affected by even the most subtle increase or decrease in the number of any species. If, for example, the population of frogs increased in the above food chain, then several changes might take place:

1)       The number of grasshoppers would decrease because there are more frogs to eat them.

2)       More snakes would come to the habitat and prosper because there are more frogs to eat.

3)       Because there are more snakes, the number of rabbits will deplete as they will be eaten by the higher population of snakes.

Consider what might happen if:

a)       The population of mice increased

b)       The population of rabbits decreased

c)       A drought led to a poor crop of grass

Whether their population increases or decreases, each species within a habitat will be affected by changes in population to some degree.

If your class is interested in getting to grips with food chains, our app Pairing for Early Science introduces them with the foundation science vocabulary to get them started!

Below: predator extraordinaire, office cat, aka Mr Worthington

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Shadow play

Shadow puppetry is an ancient form of storytelling through the use of puppets and light. It began about 2000 years ago in China when an emperor’s wife died, and his court created a shadow version of her so that the emperor could see her again.

Shadow theatres are still used today. Check out these people building a car out of just a few props!

You too can do it at home with just a torch and some paper shapes. Ask an adult to point a torch at a wall a couple of metres away. Then hold paper shapes between the torch and the wall to cast shadows on the wall. Here’s a good guide for making shadow puppets.

From animals to trees and smiley, sad and scary faces, you can make all sorts. Even your hands can create different animals – though some are more complicated than others! Can you guess what each animal is?Image

Shadows are made when an opaque (non see-through) object blocks light. The size and shape of the shadow depends on the distance between the light source and the object casting the shadow as well as the distance between the object and the surface on which the shadow is cast. The closer you move an object to the light source the bigger it gets. Try it – if you hold your hand ten centimetres from the torch it blocks out much more light than if you hold it a metre from the torch.

 Good luck casting shadows – let us know if you get any good ones!

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