This will give an idea of size differences between the two. Click on the high light to see the video–it may take a few moments to buffer or you can just see both animals as stills.
This video was taken on Jan. 21, 2011 at 5 am of an adult coyote
This was taken by the same camera on Jan 22,2011 at 3 am. Note the coyote’s tracks are still there. It is a grey fox which would make it about the size of a beagle.
BTW, the coyote came across the pond whereas the fox came out of the woods below it. The fox seems to be checking the direction from which the coyote came. Our house is about 80 yds to the left and up the hill from this spot.