If both of them were travelling anti parallel to each other. (parallel but in opposite directions)
Germ cell's I believe. These are cells that includes half your genome in order to reproduce.
I would say the food availability for gray squirrels will be affected because we do not know their diet. It also say that the red squirrels and the black squirrels have the same diets meaning less food on the Island for the grey squirrel( depending on what he eats. )
