As a general rule, it can be quite risky to house two kinds of birds together in one cage. In this case, however, the budgie doesn't play the weak part. More likely the canary will be in danger. Budgies can be quite pushy to other birds, they are even bold enough to attack a cockatiel (even though the cockatiel is more likely to win from the budgie). Don't confuse cockatiels with lovebirds though, because lovebirds can't stand budgies and will kill them when they come too close.
After some research on the internet, I confirm that I don't recommend keeping budgies together with canaries or any other domestic finches because:
- Finches are smaller than budgies and are not able to defend themselves, should the budgie decide to attack
- Budgies can hurt the canaries badly: they can take off their beak or feet
IF you still want to give this a try (after all, canaries don't eat the budgies' food and are almost the same size as them), then you should do the following things:
- Make sure the budgies and canaries are raised together as babies
- Supervise them frequently, see how they are getting along. From the moment they attack one another, put them apart forever.
- Provide a big space for both species so that they don't start fighting over who is allowed to sit or sleep where.
- Keep an extra eye out when the budgies or canaries start breeding. Females tend to be more aggressive when they're in breeding mood.
The canary is like "Dude... chill out!"
Other posts in this series:
Can budgerigars and lovebirds live together?
Can budgerigars and cockatiels love together?