I Observe That Squirrels That Live in the Southeastern United

I observe that squirrels that live in the southeastern United States are much thinner than squirrels that live in the northeastern part of the country.I theorize that this is because the squirrels that live in the northeast have greater fat reserves for the winter months when food is scarce.Is this a scientific theory?

A) Yes,it is a good educated guess.
B) Yes,I am taking into consideration physiological reasons for their larger size,so it's scientific.
C) No,it's just a hypothesis;it has not been proven to be true through extensive experimentation or quantification.
D) No,it cannot be proven true.
E) Yes,I theorized it so it qualifies as a theory.