The bird -- an accipiter -- set about plucking feathers. An hour later, after surveying the dining spot, I determined that we had one less junco in our yard.
After a half hour, the accipter paused to rest. I thought it was finished, but after 10 minutes it resumed feeding. This gave me time to set up the spotting scope and focus in on its features. After peering at the bird, looking at several bird books, and reading Tricky bird IDs: sharp-shinned hawk and Cooper's hawk at Project Feeder Watch, I concluded that our accipiter was a female sharp-shinned hawk. Here is why:
- Square tail -- clearly seen while it was feeding on the junco; Cooper's have a rounded tail
- Reddish color below eyes and around to "cheeks" -- this is a lighter color in Cooper's
- Relatively small head and beak
- Broad chest - center of gravity high; this was particularly evident when it was resting between meals and facing us