Bird Watching: Is this a Swallow Tail Hawk?, 1 by Rosemack

Rosemack wrote:
Day before yesterday, two hawks appeared that were absolutely beautiful. I have one picture of one sitting in a tree and the other flying... (boy was it hard to catch). I wish I had a better camera, one with a zoom. Anyway, this is the picture I got that was the best so far. They were attacking baby birds in our pecan tree. It broke my heart, as the babies were "crying" and the mama's were circling the hawk and trying to attack it... which was an impossible mission. The hawk was eating what it had in it's feet and when it would drop a "particle" would dive down and catch it. Truly amazing to watch, but hearing the babies broke my heart. I understand that creatures eat creatures to survive.... but I cried. It was so sad to hear. Can you definitely identify this as a swallow tail? And is that normal for them to eat the baby birds?