We get wedgetail eagles here. Wingspans up to 10', weighing about 20 - 25 lbs. In summer they can often be found at heights above 10,000'. They usually hang around soaring at the top of convection looking for food on the ground, and when they find it they tuck their wings in and descend like a bullet, flaring and reaching out with their talons at the last second to grip their prey and loft it skyward.
They can spot a fieldmouse from about 8000'.
We see a lot of them in gliders. For most times of the year they're pretty benign, and will happily share thermals with us, occasionally coming in close to play in the wingtip vortices. I've had one of them formate on me close enough that I could see the feathers around his eyes rustling in the slipstream. One of those amazing experiences that you can only explain to other aviators.
We give them a wide berth during mating season, because they can get pretty aggressive and territorial. When they want to attack they'll position themselves above and behind you in the sun, then dive-bomb towards you. They'll typically aim for the canopy or the ailerons, probably because they usually disable other birds by going for the eyes or the wingtip feathers.
They almost always miss to the aft (no sense of scale, no idea of how big we are, upsets their aim and timing?)
We can use them as thermal markers when flying cross country on blue-sky days. If you see two or three of them circling in the distance, it means there's a thermal there, and they aren't feeling territorial (if you see one of them circling alone, there's lift but maybe he's too aggressive to have companions)
I've seen a couple of cases of people hitting them by accident. They make a bit of a mess of the leading edge, not the kind of thing you'd want to make a habit of. I think it's very, very rare.
- mark