call ducks are smaller, suppose to be under 2 pounds,
and louder.
and wild mallards are just that, wild.
call ducks are domesticated and bred down from mallards (at one point in time)
calls were bred to be live duck calls, they were small enough for hunters to easily carry and were used to...
they are most likely wild mallards, there are no wild call ducks. and will move on their way.
but i second the idea of a larger flock, there is safety in numbers