Wild zebra finches?? Or just escaped pets?

Ok so this is really weird. So I have exactly 13 zebra finches. Well I originally had 13. I now have 19. I keep my finch cage outside. I sometimes let them out of the cage for free flying which they really love. I do it about an hour before feeding time so I can call them back with food pretty quickly. I don't do this very often but maybe a couple times a month.
So about 3 weeks ago I let my birds out for a couple hours before I feed them that morning. I called them back and I made sure I had every one of them. I leave the cage open while they eat because there are always a couple stragglers. And I always count my birds. When I counted them I counted 15 which completely blew my mind! And then another one flew in a couple minutes later. The next day only half of my birds came back on time and then after feeding they all came back with 3 more zebras and like a society finch (I think). I've been living here for a very long time and I have never seen any zebra finches flying around. I hardly see any birds flying around except the occasional robin.
I captured the stray birds and they're in the aviary now. I'm kinda scared to let my birds out because I feel like they might go to wherever these new birds came from and stay lol.

That's really interesting.

I let my bird out to free fly too like you.... zebra finches, zebra doves, ring neck doves, diamond doves and others... only never had any luck with the budgies.. they seem really dumb and just stray off... not keeping in a flock like I thought they would.

I think the birds you have are escaped ones... because is very rare for people to free fly them... and also they will not be wild as they can't survive in the wild for long.

Its likely that someone has an aviry in their yard in your area.. and either the zebra fiches escaped or they let them out as they no longer wanted them.

Sounds like they will have a lucky home with you.

As they are always attracted to join other zebra finches I think they will stay with yours... Small flocks or single birds will always join a bigger flock... so I think your birds will stay together as you have a lot.. and they wont go off with any other stragglers.

Please post some photos of your birds on here.. I love to see how other people keep them.