With no basis or purpose really, I started comparing these two dooryard familiars. They are about the same length (16-21 in) and weight (12-21 oz), but there the resemblance ends. Obviously one is a mammal and the other is a bird. What seemed interesting and comparable were their social lives. Crows and squirrels are always interacting, but never the one with the other, only squirrels with squirrels and crows with crows.