All behavior serves a purpose for the animal, even aggression. All behavior happens for a reason. If you can identify that reason, then you have identified the reinforcer for that behavior. Once you have identified the reinforcer, you can then begin to change the behavior.
A reinforcer is something delivered after a behavior that causes the future rate of that behavior to maintain or increase. Many people think reinforcers are treats or rewards. This is not the case. Reinforcers can be treats or rewards but they can also mean it serves a purpose for the bird and that undesired behavior therefore will maintain or increase. Let me give two examples.
You ask your bird to step up onto your hand. It steps up and then you deliver a head scratch, a treat, or the opportunity to cuddle. If the future rate of that behavior increases, then the head scratch, the treat, or the opportunity to cuddle is a reinforcer for your bird. Reinforcers are not only food or treats. Around here, attention and the opportunity to get petted is a highly valued reinforcer of many of the birds. Your bird is always the one that decides the reinforcer; it’s never us. This is a key point I see very commonly misused.
So commonly I see aggression being reinforced in the companion animal world. My second example: If I ask a bird to step up onto my hand and it leans away from me, that is a pretty clear indicator that the bird does not want to step up. If I push my hand further, the bird may growl. If I persist, the bird may lunge. I have reinforced all of this undesired behavior because the undesired behavior maintained or increased. In this instance, it increased. When I pull my hand away from the open beak, the bird has learned the lunge or open beak gets it what it wants and it will resort to that behavior quicker with the next encounter because the lean and the growl didn’t work. We have reinforced all of these undesired behaviors.
I don’t want to get bit and try my hardest to never put myself in a situation where I will get bit. These forms of body language and communication serve a purpose for the bird. The first thing I will do is work at the bird’s pace and comfort level. I will not push the bird past its comfort level or I could easily reinforce the aggressive behaviors. I first identify the bird’s favored treats, foods, interaction (if any) and I will deliver them for the bird allowing me to get closer and closer.
Aggressive behaviors such as lunging, open beak, biting, flying at your head and hitting you, chasing you across the floor are all learned behaviors and that bird has learned these forms of communication work and serve a purpose for them. These forms of communication can be changed and you can teach an old bird new tricks. I do it all the time.
Identify the desired reinforcers and deliver them for close proximity or calm behavior. Consistently pair yourself with the delivery of these reinforcers while never pushing the bird past its comfort level. This is a very important point. If you do this in short amounts of time and frequently, you will begin to see the behavior change. Look for the really small steps of behavior change. Within these small steps you will see the change. When first trying to change behavior often I will have to use favored treats. If I am consistently pairing myself with the bird’s favored treats or other reinforcers, soon I see the reinforcers begin to change from food to the opportunity to spend time with me. This is reinforcing to me and this is the relationship I want with a bird that I will spend the rest of my life with.