It is indeed funny what can be associated in the mind of your subject critter.

Several weeks ago I was out hunting and had a new apprentice I am working with along. We had already discussed Operant Conditioning, but she had not really applied the concept yet. She also had mentioned in some prior conversations that she was nervous about dealing with aggression. The goshawk that I am currently flying had been rather hot on the aggression scale especially in her earlier seasons, but does on occasion have a slight relapse. After we were done with an unsuccessful day of hunting in one of my regular spots, we were strolling back towards the car chatting, and walking through the spot where in retrospect I realize I normally call my hawk down to the lure at the end of the day. I also had been thinking I would call the hawk down, so I likely was giving off some cues that my hawk was keying on. At any rate, she was 150 yards away in a tree, and came at me calling impatiently. I knew this was going to lead to her bullying me by latching onto my leg and displaying.

I normally would have done what I could to avoid rewarding this behavior, and presenting the lure after she had settled down, but decided this was a good chance to demonstrate OC and show some ways to smooth over aggression in small stages so I let things play out a little more than I usually do. To use OC with aggression, the basic strategy is to watch for calm body language, and tag that with a CR and reward it. It essentially is shaping the underlying emotions. My apprentice and I were actively discussing what I was doing and why, and the first calm behavior that I saw came from walking away from me after she had given up on her efforts to get me to cough up the goods by footing my boot. I tagged that and rewarded it, then worked on shaping for calmer behaviors. Now the real funny thing is that she got the link between acting calm and getting a reward (this wasnt the first time I had been shaping for that specifically, but it had been years since I had to be this active on working on that). However, she thought that footing my boot was a pre-requisite to being rewarded for acting calm. It was actually pretty funny watching her with a calm demeanor, including a fluffed up baby face, walk over and gently foot my boot and then happily walk away so she could get the CR. Even though I began actively looking for opportunities to CR her before she had a chance to put her talons on my boot, it was very firmly ingrained.

A couple of months later, it is still very common for her to gently foot my boot and walk away to solicit a click and a tidbit even though I have never rewarded that since that day.

Its a really complex thing to evaluate intelligence, because it is so easy to fall into biases along the lines of "oh, you thought exactly the way I want you to! Arent you a smarty pants!!" A lot of this has to do with why Harris' hawks are perceived to be very intelligent. However, all falcons and all hawks are very good at putting together a chain of events that led to something. As a rule, they will do this much faster than people will. On the plus side, that means they can learn complex chains very quickly. On the minus side though, they are very susceptible to prejudices and superstition. My goshawks regularly get superstitious that they will see game if they sit on a particular branch in a tree, often from one exposure.