Food Chains, Scavengers & Decomposers

1. Food Chains, Scavengers & Decomposers “they’re everywhere!”

2. What’s A Food Chain? • Scientists use a kind of flowchart called a food chain to show how living things are connected together. • A food chain is a convenient way to show how energy moves among living things in an ecosystem. • Some food chains are longer than others, and more than one consumer can be part of a food chain

3. For example…

4. Scavengers & Decomposers • All living things eventually die (sad, isn’t it?) • All consumers generate waste materials from the food they eat (gross, isn’t it?) • Our planet would be covered in dead corpses and waste materials if not for a special group of consumers. • These consumers get the matter and energy they need from wastes, dead plants and dead animals • They are known as scavengers & decomposers!

5. Scavengers • Scavengers are consumers that don’t usually kill for their own food. • Instead, they feed off the remains of living things that are killed by other consumers. • Crows, Ravens, and housefly larva (maggots) are examples of scavengers.

6. Decomposers • Decomposers are consumers that break-down (decompose) animal wastes and dead plants and animals. • Fungi such as mushrooms and the mould you see growing on bread, fruits and vegetables are decomposers. • Many kinds of bacteria are also decomposers.

7. Decomposers Are Essential • Decomposers keep us and other living things from being buried in dead bodies, feces and urine • Their actions mean that plants always have a supply of nutrients available to them

8. Class Work • Read pages 42 &43 in our Science Power 7 books • The Clean-up Squad: Scavengers and Decomposers. • In your science notebook define each of the following terms and give an example. • Scavenger, Decomposer, Micro-organism • Also answer • Why are scavengers and decomposers essential to food chains/webs? • It is too noisy!