There is one species, particularly in the winter, that is reliable and distracting: Cooper's Hawk. I've seen this species catch House Sparrows at our feeders, even stalking them on the ground. Last year, I had one pick off a chipmunk just as it was warming up outside.
Yesterday there was a large female just off the road that was obviously excited about something - tail and head twitching.
Today, she was back an I investigated the spot from where she took off. Apparently, she was able to kill a Mallard. An impressive kill for this size of bird. And a young bird too - the yellow iris indicating a hatch year bird. Females are larger than males and weight about 600 g and female Mallards are over 1000 g. Yea. I found the head of the duck about a km from the Susquehanna R. Did she kill it there and try to fly off with it? Was the duck flying in? Did she consume most of it somewhere else? I only found the head and some skin connecting it to a foot. Impressive. Could a hunter have disposed of it and she was scavenging? Anyways, here is the duck and her.