Of the e-mails I receive each day, two questions keep coming up. Can I house canaries with Finches? Can I house Parakeets will Finches? In my opinion the answer to both questions is no. Now I'll explain why.
Question: Can I house Canaries with Finches?
While technically you "can" house Canaries with Finches I don't think you "Should". Canaries and Finches are alike in many ways. Diet isn't one of them. Canary seed mix is quite different from Finch seed mixes. Canaries are also often given additives for molting, song, breeding, color, and feather quality. These additives can be given to finches but they don't always have the same result. Sorry your white finch won't turn red pink.
The dietary differences between these species can lead to health problems for both the Canaries and the Finches. Supplying both types of feed to your mixed flock is one solution but what can you do if the Finches prefer to eat only the Canary seed and visa versa?
Behavioral differences are one problem very few run into. Thankfully Canaries aren't very aggressive towards finches and Finches tend to leave Canaries alone. Some species of Finch such as Weavers are quite aggressive towards most everyone and may attack an unwary Canary.
There is also a possibility of cross-species breeding. While a Canary and Zebra cross will probably never happen, a Canary and Goldfinch cross is very possible. These offspring (referred to as Mules) are not good breeding or showing stock.
Question: Can I house Parakeets with Finches?
No. Never. Just don't do it please! The result is almost always a bloody massacre. Parakeets are Hookbills, and Hookbills should never be housed with Finches. Whether you have a fight cage with only a few birds or a large backyard aviary with many birds; you never mix Hookbills and Finches.
As you know if you have owned any Hookbill parrot in the past, they like to chew on everything. They will chew on perches, toys, cage bars, your clothing, and even your finches. I don't know if their intention is always to kill or simply to play with the finch, but the finch is almost always killed.
I have been called to many homes and businesses where Parakeets have recently been added to the aviary. The aviary owners want to know what is wrong with the finches, because they keep dying. I stand quietly and watch the birds interact and force the owners do to the same. In most cases I've only needed to wait a few minutes.
The reason for the Finch deaths becomes very apparent as we watch. A Parakeet grabs the finch and either rips out a beak full of feather or crushes the tiny finch's head or neck. When the feathers are plucked it's a good sign that the Hookbills have been trying to catch the Finch but missing. Eventually they will get a good hold and deliver the one crushing bite that ends it all.
Crushing the head or neck is the quick way for the Finch's life to be ended. I have seen too many finches dismembered by larger Hookbills. Now that is a very bloody mess to clean up.
Now if you ask around, you may find breeders who house Finches with Hookbills in very large aviaries with no problem. These are few and far between. For the ordinary bird fancier I strongly suggest you never put Hookbills within reach of your Finches.
As a side note I will also point out that not all Finch species are compatible either. Many finches are just as aggressive and violent towards other Finches. Always learn as much as you can about any species of bird before bringing it into your home and into your current flock.