One of the first rules of animal training is to know as much as you can about the animal you're working with. At bare minimum, you need to know what that individual finds reinforcing and punishing. That knowledge is, however, the bare minimum. The more you understand the natural behavior of the animal, the better able you'll be to meet his needs and set you both up to succeed.
I've been reading the posts on the Bird-Click mailing list. I'm not a bird trainer, per se, but I've participated in several Bailey chicken camps, and I've trained dogs and horses. So I joined the list feeling fairly confident that I had a good grasp of what I needed to know to train birds. Instead, I found that I needed to sit in the corner with a healthy helping of humble pie and spend some time getting to know my animal!
One of the first things I learned was that different types of birds are as different as different breeds of dogs. Each species is unique, even compared to closely-related species. Some are more friendly than others. Some get aggressive when hormonal. Some are easier to train. Some learn some tasks, like retrieving, more easily than others. Some are more noisy, others less so. Diets vary greatly, as do treat preferences. All of the birds are intelligent — some are scary brilliant.
The list members are quick to help newbies understand their species of bird and to guide them to activities that will help them be quickly successful. Not surprisingly, some people choose birds that really weren't the best choice for their household. I'm not planning on buying a bird in the near future, but I've considered it before. No doubt I'd have chosen exactly the WRONG one. I feel more confident now. Without a doubt, one thing this experience has taught me is that, before I expand into a new breed or new species, it's important to do my homework and make sure that we're going to be a good match. If I decide to get a bird, I'm going to Bird-Click first!