A researcher investigates how camouflage affects the survival of lizards against avian predators on a dark volcanic basalt landscape.
She places 650 silicone model lizards across the habitat. She colors 400 of the models dark to match the dark basalt ground, and 250 of the models light so they are highly visible.
She leaves the models overnight and returns the following day to inspect them for signs of predator attacks (such as peck marks and tears).
The bar chart shows her results:
Calculate the difference between the number of damaged light model lizards and the number of damaged dark model lizards.