Pituitary gland is the master gland
A. The birds had beaks that were adapted for feeding differently
<span>Leptin, a hormone predominantly made by adipose cells that helps to regulate energy balance by inhibiting hunger, is the hormone secreted into the bloodstream by fatty tissue to signal the hypothalamus that the body has enough food.</span>
Light pollution<span> is excessive and inappropriate artificial </span>light<span>. The four components of </span>light pollution<span>are often combined and may overlap: Urban Sky Glow—the brightening of the night sky over inhabited areas. </span>Light<span> Trespass—</span>light<span> falling where it is not intended, wanted, or needed.</span>
There is no answer that is right except for C. Natural Selection.
Genetic Recombination doesn't change gene frequency;nor does migration. (Unless it's local)
Mutation could be the answer, but since mutations are too rare to really power Evolution, the only logical answer is Natural Selection.
