In most bird species, only the male sings and then only in his territory during the reproductive season. This is to attract females and to ward off other males, which serves to improve their chances of mating. This behavior demonstrates:

In most bird species, only the male sings and then only in his territory during the reproductive season. This is to attract females and to ward off other males, which serves to improve their chances of mating. This behavior demonstrates:

a. that physiological explanations are preferred over other kinds of explanations.
b. learning during a critical period.
c. that physiological, ontogenetic, evolutionary, and functional explanations are mutually exclusive.
d. how physiological, ontogenetic, evolutionary, and functional explanations can all be used to explain the same behavior.