From: Winnipeg, MB
Orm, I did have one occasion (I got no pics) where there were two red-tailed hawks working like a team trying to catch a squirrel, and there were about four around for them to chase. The squirrels didn't seem overly upset about the hawks (red-tails are among the largest hawks around here) and easily outmaneuvered them repeatedly. One was quite large, a female I presume, the other smaller, either a male or a juvenile. They spent an hour chasing these squirrels around, not with such vigor that they'd be exhausted, though. The next day on my walk to the garage I encountered a squirrel skeleton. There was the spine, parts of the limbs, a bit of the tail but no skull. We do get around here barred owls which are quite large and could easily take a squirrel, but the squirrels usually are in bed by the dusk hour and are quite cautious coming out in the dawn hour. I really hate the squirrels because they do a lot of vandalism of all sorts. I really love the hawks.
edit: I meant to say, it's really difficult to tell various hawk species apart. There's one called the Cooper's hawk where if you get a real clear look at the tail feathers you can identify them. These two hawks could have been among two or three other species, but at one point I heard (and saw) the female call to the other one, and there was absolutely no doubt that they were red-tails.
So you like hawks, eh? Well what is this one? Barred Hawk? Hairy Faced Hawk? Squawk Hawk?
No matter how bad a situation is, you can always make it worse. - Chris Hadfield : An Astronaut's Guide To Life On Earth