Per Cliff Clavin;
*November begins the period of long nights, where as the Sun sets very early and during the colonial period there was a lack of indoor lighting. Being that candle wax was rare and difficult to make and whale oil for lamps very expensive, such were only used at night for cooking and eating. The man of the home thus only got to see his wife's beaver at night during periods of the Full Moon shining through the windows. That is what we now call the Beaver Moon.
Cliff Clavin was a wise man.