Is it okay to have one Zebra finch?

Having just one is a lonely life for this kind of bird. They are a community species and thrive best with others. If you do not want babies, a single female is not always advised, two or more females is best. A male and a female could be ok, but do not provide a nesting box or place they can set up shop. But do have someplace they can keep warm together and cuddle. Having two males only can sometimes be a slight problem at first. It is a territorial thing and they can bicker. If you get them together from the same bunch, there is a better chance they are acclimated to each other. I have raised them for many years and never had less than five. They are much healthier and happier with friends. Not only that, they sound so cool together!!!!!