Answer:
See the answer below.
Explanation:
The bird preferred to eat the brown frog instead of the red and blue frog because the red and blue colors serve as a warning to the bird. The bright color is a type of adaptive attribute known as warning coloration.
Most brightly colored preys are poisonous and bright the color is there as a reminder and a warning to potential predators. Hence, the predator bird in the illustration would rather eat the brown frog instead of the poisonous red and blue frog.