Janice VanCleave’s Crazy, Kooky, and Quirky Biology Experiments
Coated Purpose To demonstrate the effect that oil spills can have on birds Materials 2 small bowls tap water 3 tablespoons 45 ml oil two 2 to 3-inch 5 to 7 5 cm long feathers can be purchased at a crafts store NOTE Do not pick up bird feathers from the ground outdoors They can carry diseases Procedure 1 Fill the bowls three-fourths full with water 2 Pour the oil into one of the bowls 3 Gently lay one of the feathers on the surface of the water in the bowl without the oil 4 Lift the feather from the bowl and blow on it 5 Gently lay the second feather on the surface of the oil in the second bowl 6 Lift the feather from the bowl and blow on it Results The feather taken from the water appears dry and is light enough to be moved by your breath The feather taken from the oil appears wet and heavy It moves little or not at all when you blow on it Why Water does not stick to the feathers of birds very easily but oil does The oil-coated feather is very heavy and the fibers of the feather 8 Janice VanCleave’s Crazy Kooky and Quirky Biology Experiments
stick together This experiment demonstrates how oil from oil spills can mat the feathers of birds and make the birds too heavy to fly This makes the birds easy prey animal hunted for food to predators 9 Coated
too MuCh too Fast Purpose To demonstrate the effect of overfishing Materials scissors 2 dishwashing sponges ruler large bowl of tap water 2 tea strainers 1 small 1 large small bowl pencil writing paper helper Procedure 1 Cut each sponge into 1-inch 2 5 cm cubes 2 Place ten sponge cubes in the bowl of water spreading the cubes over the water's surface 3 Ask your helper to close his or her eyes and move the small strainer through the water once to scoop up as many cubes as possible 4 Remove the cubes from the strainer and place them in the small bowl 5 Count the cubes remaining in the water and add an equal number of cubes to double the amount of cubes in the water 6 Repeat steps 3 to 5 three times On the last scooping do not add any cubes Record the number of cubes in the water 7 Start over with ten cubes in the water 8 Ask your helper to do steps 3 and 4 four times using the large strainer Do not add cubes between scoopings After the last time 10 Janice VanCleave’s Crazy Kooky and Quirky Biology Experiments
count the cubes remaining in the water and add an equal number of cubes to double the amount of cubes in the water Record the number of cubes Results The number of cubes in the bowl of water increases when the small strainer is used and cubes are added after each scooping The number of cubes greatly decreases and may even be zero after four scoops with the large strainer Why The sponge cubes represent fish and the strainers commercial fishing nets Scooping with the small strainer is like fishing with fewer nets and catching fewer fish Adding cubes represents reproduction of fish Commercial fishing boats haul in more fish Overfishing removes fish faster than they can reproduce as demonstrated by using the large strainer and not adding cubes after each scooping Some fish are in danger of becoming extinct no longer in existence because of overfishing 11 Too Much Too Fast
