Thanks for asking first before you added a canary to the flock.
No, you should not add a canary or any other breed into the parakeet flock. They wouldn't get along and might harm each other. If you want a canary, you should buy a cage just for that bird.
Also, I'd recommend getting a larger cage for your two parakeets. Your current dimensions are barely big enough for one parakeet let alone two. Sometimes you can find reasonaly priced cages online at E-Bay or Petsmart, Petco, Dr. Foster, etc.
Finally, training two birds at once is much harder than training just one. They tend to bond with each other and not you. You may have to train them separately.
This site has loads of information on all the above topics.
Last edited by Anon.; 06/26/10 04:31 PM.