Up, 'cause I just got back from a holiday in Arizona, where I spotted a new-to-me species of hawk while walking around Papago Park in Phoenix. We were standing on top of a butte Sunday morning when I noticed three raven sized birds flying toward us. They glided right over the top of us, and I was able to get a good look as they passed overhead. They then started spiraling upwards, reaching a high altitude, at which point they soared off in the blue yonder in a single file stretching for hundreds of yards. Simply breathtaking.
After doing a web search, I decided that they were almost certainly Harris's Hawks.
http://www.greglasley.net/harrishawk.html
http://identify.whatbird.com/obj/475/_/Harriss_Hawk.aspx
Here's an interesting tidbit; they actually hunt in packs:
Food: Harris's hawks employ one of the most sophisticated cooperative hunting strategies in birds. Hunts medium-sized to relatively large mammals (hares and rabbits), birds, and lizards. Two methods of hunting: 1) sit and wait (often employed by lone hawks); 2) short-flight-perch hunting. Cooperative tactics include (1) surprise pounce - several hawks coming from different directions; (2) flush and ambush - 1 or more hawks penetrate the cover while others watch from nearby perches and attack when prey is flushed; (3) relay attack - long chase of hares while the lead "chase" position is alternated among hunting birds. Energetic analysis shows the maximum food availability per individual is obtained by groups of 5 hawks, the most common size. They feed in order of dominance; alpha breeding female (most dominant), alpha breeding male, beta male, and 0-4 birds. During nonbreeding season, a group of hawks will guard/feed on a large carcass for more than 36 hours, and cache carcasses.
What's funny is that when we saw them flying by, there was a name on the tip of my tongue that started with a "b". Turns out that the Harris's Hawk is classified as a "buteo", which was the word I was trying to remember. I used to just pore over bird books as a kid, and amazingly, when I see a new species, the name sometimes pops into my head.
p.s.
Impossible, you'll want to check out www.whatbird.com. There's a forum where you can ask the experts, and an excellent bird ID search function on the main page.