It is a case of trying them together,it sometimes works,but have a spare cage ready in case it does not work out.They will not get along if you add nesting material.

Hi I have a large cage and I have a pair of male and female green singer finches I also have a pair of male and female zebra finch's . They have been getting along well without any agresssion for about 4 months. I know that based on this finch compatibility chart they normally wouldn't get along since they are not in the same category, but, would the red-billed fire finch get along with my zebra finches they are not an aggressive pair.

Thanks,

Preston