We have an acre pond and were raising Mallard ducklings. At 5 weeks old I moved them into a sturdy pen with a house. One was snatched from the pen and eaten. There were a couple small feathers and a 1.5" piece of bone left. I covered their pen with chicken wire. At 10pm heard quacking. There was a huge Hawk looking bird on top of the pen trying for another kill. I have not seen one this big in our area and from what I read Hawks do not hunt at night. It was dark so I couldn't see much but the shape. It did sit on the ground a while before we scared it off. Our ducks are nearly the size of a full-grown Mallard. Are there night hunting Hawks or other night birds? I have seen migrating Ospry on occasion. It did not seem to be upright like an owl. Thank You.