As you can see the four beasts in the picture are chilling in the cave. But one stands out from the bunch. The three red and black beasts blend in with the dark shadows of the cave. Will that beast survive?
The dragon on the left was not able to survive due to the bright color of it's skin. It was not able to hide from the other beasts in the cave as for them they can easily go unseen in the deadly horror shadows of the cave.
The three beast will survive and reproduce while the the other animal was killed off.
The dragons on the far side are the quickest in the air and can reproduce better and more frequent than any other species in the cave.