The population size of a predator species is directly controlled by the population size of it's prey. If the predator has no prey the population size will go down because they have no food.
Answer:
Using the number of amino acid differences, it would appear that the two birds are more closely related (had a common ancestor very recently), while the two fungi would have to trace their common ancestry much farther back in time (much more distantly related).
C. Half shaded and half white.
Their gravitational pull towards the planet?