When it comes to identifying tree squirrels, size does matter. This is another photo I took of the Eastern Fox Squirrel yesterday. In this photo he is stretched out along the top of the chain-link fence. I later measured the squares in the fence and they are three inches across. Counting the squares of the squirrel’s length I can safely say he is over seven links long, so 3x7=21 inches. This narrows down the choices. The closest squirrel in color is the Douglas Squirrel which is definitely smaller. Squirrels are measured from head to tip of tail. Douglas Squirrels range from 11-14 inches. Eastern Fox Squirrels measure from 18-28 inches, making them the largest tree squirrel in North America.