Surf into Science 3:	Food Chain Rivals				


The student will be able to:

·	identify the terms: predator, prey, grazer, scavenger, parasite and
decomposer.
 
   
Activity:
 
Scavenger Hunt

Arrange the students in groups and take the students outside for a scavenger 
hunt.  Give the group a list of items you want them to search for in the 
immediate vicinity of the school eg. tin can, dead leaves, wrapper, etc.

Set a time limit of 20 minutes for the students to find as many of the items 
as they can. 

Bring the items back to the classroom.

Discuss how the students were like scavengers (eg. crow, seagull, vulture) 
themselves.  Lead them to realize that scavengers are very important in 
keeping the environment clean.  Just imagine how terrible it would look if 
wild animals killed by automobiles or dead fish that were swept ashore by 
the waves, were not disposed of by scavengers and decomposers.  Not to 
mention the bad smell from those animals!

Discuss the purpose of predators in the forest - that they control the 
numbers of prey in a forest community. 

What role does a grazer (eg. cow) play in the community - provides food 
(milk and beef). 

How might a parasite cause harm to a dog? 

Keeping the students in their groups, give each group fifteen pictures of 
different organisms.  Their task is to look at each picture and decide if 
the organism in the picture is a predator, prey, grazer, scavenger, 
parasite, or decomposer.

Assessment:
     ·	Observe the student interactions during the scavenger hunt 
     ·	Observe and listen for their contributions to the discussion 
     ·	Circulate and discuss student reasons why they labelled the 
        organisms as they did during the picture identification.