Swainson's Hawks

I left early this morning to go by the bank on the way to my store. Coming down off the hill, I looked over some fields and saw 4 groups of about 20 birds each, circling around. They were fairly high up but I could see they were not ravens or anything else I recognized. I pulled over to look better. There were different color variations--some were very white on the underside, some were dark on the underside, and others were various in betweens. All had a dark band at the end of the tail. I kept thinking they sure looked like hawks, but hawks are solitary.
Finally, a memory surfaced--in Borrego desert each spring, volunteers sit out and count the Swainson's Hawks as they migrate. Well, what migrates north in the spring has to go south in the autumn. These were Swainson's Hawks! WOW--I've been here 27 years and have never seen them. I was just in awe to be able to have seen them, all heading towards Borrego. If I had been 5 minutes different down the hill, I would have missed them. Wow.
I checked a bird book at my store and sure enough, they were Swainson's. The color differences are typical of this hawk.
Wow...