Iobserve 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?

No, it is not a scientific theory.

Explanation:

A scientific theory is a proposition that is made to explain the various phenomena that are occurring in nature and it is supported by experiments that have repeatability and well-analyzed results. Scientific theories are usually tested in experiments under controlled conditions and verified as well.In the given situation, the theory made by the observer is not being tested through any experimentation or quantification and therefore, it is just a hypothesis and not a scientific theory.