On your way to school have you ever noticed the behaviours of animals in the environment? Animals satisfy their needs one self or in teams. Security, food, habitats are some of their needs. Let’s do the following activity to find out about the food that animals consume.

A grade 6 student observed a guava tree in his home garden for several days. The following table shows his findings.

According to the data in the above table there are different connections between animals and plants for food. They can be displayed using arrows.

Connections between animals for food can be displayed in the same method.

10.1 Food Webs

The above interactions between plants and animals and animals and animals can be shown as follows.

The following figure shows the interactions among plants and animals in a piece of grassland.

Figure 10.2 shows that there are a lot of interactions among plants and animals for food. Also, it shows that they are inter- connected. They are connected as a web.

A diagram that shows the inter relationships among animals and plants for food is known as a food web.

10.2 Mode of Nutrition of Animals

According to the figure 10.2 there are many animals that feed on grass. Cow, grass hopper, caterpillar are some of them. Grass is the staple food of cows. Leaves and tender leaves of grass are eaten by caterpillar and grass hopper. The animals that consume only plant materials are known as herbivores. Cow, rabbit, deer, giraffe, grass hopper, caterpillar, elephant are some of the herbivorous animals.

Identify the food consumed by magpie, lizard, and rat-snake in figure 10.2.They feed on herbivores. Animals that consume flesh of other animals are known as carnivores. Wolf, leopard, lion, tiger, rat-snake are some examples for carnivorous animals.

Find out the food materials consumed by the animals such as crow, hen, cat, dog, cockroach, pig etc.They consume both plant materials and flesh. Animals that consume both flesh and plant materials are known as omnivores. Black bear too is an omnivore.

Animals can be categorized based on the modes of nutrition.

They are

● Herbivores :- Animals that consume only plant materials.

● Carnivores : - Animals that consume only flesh of other animals.

● Omnivores : - Animals that consume both flesh and plant materials.

Sometimes problems occur when the animals are categorized distinctly as herbivores, carnivores and omnivores. So, the feeding mechanisms of such animals have to be observed for a long time period.

Some carnivorous animals have become omnivorous because they live with human beings.

E.g. : dog, cat

10.3 Food Chains

Figure 10.6 shows a food web in a forest.

A connection that can be seen within animals for food in the above food web is shown below.

According to the above connection the plant supplies food for the rabbit.

Then, the rabbit becomes a food for the leopard.

So, the interactions for food start with a plant or part of a plant and

connect with each other as in a chain.

A linear sequence that starts from a green plant and shows the flow of

energy from one living organism to other is known as a food chain.

The followings are some food chains taken from the food web in figure

10.6.

Now it is clear that a food web is created by inter connections of several food chains.

Links of a Food Chain

The first link of a food chain is a green plant. It supplies food to the other links of the food chain directly or indirectly. Green plants use water, carbon dioxide and sun light to produce food within themselves. This process is known as photosynthesis. As the green plant produces food on its own, it is known as the producer.

The herbivores consume the leaves, tender leaves, flowers, fruits, yams and other parts of green plants. Then, the energy stored in green plants is transferred to herbivores. When the canivores consume the herbivores the energy stored in herbivores is transferred to carnivores.

Accordingly, the energy stored in the food produced using solar power by the green plants, is transferred to other consumers of the food chain. Fig. 10.8 shows this process.

The number of leopards in a jungle decreased due to some reason. So, the number of deer increased. Due to the increase of deer, their food was not sufficient. Therefore they had to compete with each other for food. Due to lack of food the number of deer decreased again.

The number of plants and animals in the environment is controlled and remained balanced due to this mutual relationship that exists between the links of food chains.

All the links of a food chain render a great service to maintain the balance of the environment. Therefore, if an animal which belongs to a particular link in a food chain is destroyed or removed, it affects the existence of other links of the food chain. This may lead to a decrease or an increase of the number of other links. Therefore, you can understand that all the living beings are important to maintain the balance of the environment.

Have you heard about pandas that live in the forests of China? Panda is a herbivorous animal. This animal has faced a threat of extinction because their only food is bamboo. Now, steps to conserve these animals have already been taken. Animals feed on a variety of foods. When there is a large diversity in food consumed by animals, their existence is more established.

Every animal has a right to live free in the environment. You as well as the other living organisms are an important part in the environment. So it is your duty not to harm animals or plants.