I could have sworn I started a thread on this subject way back when, but I can't find it. There are several of us here that have or have had horses, and I know I've speculated in the past about similarities and differences.
On an unrelated thread I posited that horses are very responsive to body language whereas parrots are more verbally oriented. Patdbunny suggested that birds also pick up nonverbal signals about our moods. I agree with that statement, but I still stand by my original assertion. When training a horse, what we do with our body is paramount, what we do with our voice is of limited relevance, and tone and intonation are far more important than actual words. For example, if I want to turn my horse at liberty in a round pen, I use my whole body to suggest that I may block the path, at first actually stepping into that direction, but later virtually just thinking it, and a horse can very acutely read that and respond to it. A small subtle hand gesture would be MUCH harder to train a horse to respond to (although not impossible).
I think a bird can pick up on our attitude but I have the sense that they read our faces, hands and voices to a much larger extent than they do our overall posture. We tend to use verbal cues and hand cues more than whole-body signals.
Another major difference IMO is that, while all animals can learn from all types of training, with horses most work is done using negative reinforcement and great skill is needed when bridge conditioning (Clicker training) is attempted. Pressure and release is the basis of virtually all horse training for normal handling. I've personally found clicker training useful to teach tolerance of procedures, where you want them to put up with pressure, not yield to it, and it is good for teaching tricks, but trying to teach under saddle work that way is practically difficult. Plus horses are SO food oriented, great care is needed to keep the interaction respectful. With parrots, positive reinforcement with or without a bridge is the go-to approach and negative reinforcement is very rarely useful.
A final difference is that while both are group-oriented animals (unlike cats), horses tend to live in herds that have a very clear hierarchy extending to many levels, and they have a persistent inclination to test the leadership. A horse that does not feel it has a leader may put itself into that position and express behavior that is problematic as result -- for example, looking for all the tigers in the world. With parrots, although some literature written 10-20 years ago espouses desire for dominance as a driving trait, modern thinking seems to be more that they are cooperative equal-independent flock members rather than hierarchical with a dominant flock member. So with birds we worry more about cooperation and less about being an authority figure, although we do need to be confident and impose a certain level of discipline, it is not as important to be "in charge" all the time.
On the other hand, as prey animals, both are very aware of their environments and both will tend to flee first and ask questions later. Both birds and horses can spook, although having a bird fly off your shoulder is considerably less of a problem than having 1200lbs of horse disappear out from underneath you.
Force, harsh dominance and positive punishment using force/pain are not very useful with any animal as far as I can tell. A dog may take it and still try to please, but neither a horse nor a parrot is likely to willingly come back for more.





