Katana has a great suggestion about places that sell cages. And just pet stores, in general. I know of at least one case where someone who found a parrot called a pet store asking what to feed it. Also the university is a very good idea. People come from all over to the university.
I would definitely spread out more. Move over toward Congress Avenue. Do hit those garages and see if you can leave a flyer at the attendant's booth. Spread out a lot wider and hit places where people shop in that area, restaurants, coffee shops, etc. Remember, with your flyers, you're not looking for the bird, you're looking for a person, and people move around a lot. So don't limit your flyers to where you think the bird may have gotten.
Great job with the radio interview! You're doing a great job.