How and Why Chameleons Change Colors

Ross, Shirley                     Neil School
14422 S. Green St.                
Harvey, IL  60426                 

Objectives:

Given a chameleon, the students will observe the color changes and 
explain the possible conditions that cause this reptile to change 
colors. 

Given a chameleon, the students will discuss the biological factors 
that cause color changes. 

Given a chameleon, the students will note the amount of time needed in 
order for changes in the pigmentary system to become apparent. 

Apparatus needed: 

4 chameleons
16 pieces of felt (4 pieces of beige, black, green, and yellow)
4 flashlights
4 crickets
4 plastic boxes
4 brown paper bags

Recommended strategy:

Divide the class into four groups.  Remove each chameleon from a 
paper bag.  Note the chameleon's color at this time.  The students 
will place the chameleons on varying colors of cloth.  Note each color 
change and time needed for this color change to take place.  Next, 
each group will shine a flashlight on the chameleon.  Again, note the 
color change and time needed for this change.  Now, place each 
chameleon and a cricket in a plastic box.  Watch for a color change 
and the time.  The students should notice that all of these factors 
could cause a color change.  However, the most influencing factor is 
light.  Explain to the students that the chameleon's ability to change 
color is controlled by hormones.  These hormones act on various 
pigments in the skin.  Special cells called chromatophores in the skin 
allow the chameleon to change colors.  You might also want to discuss 
the meaning of the words "pigments" and "chromatophores".