Clip the wings on the remaining bird and put a divider in the cage so it is separated from the part with the open door. Or, you can just leave him outside. Most domestic birds are dumber than a box or rocks and have troubles finding their way home. You should be putting up posters and keeping an eye on the local newspaper for 'found bird' ads.
Chances are fairly slim of that female coming back, if she survives or not regardless. Look online for people selling their cockatiels, you could be lucky and find another eight year old one:)
Good luck
try google it also
I had two cockatiels but recently one escape while it was being fed (got spooked). I have had them for around 8 years and they both shared the same cage and are different genders, the one left is male. When the female escaped it flew off with a bunch of other small birds and hasn't come back yet (been a couple of days). The birds are kept at a farm-like area but with many pine and willow trees. There is also a large river nearby.
I've thought about getting another bird so the male isn't lonely but what if they reject each other? Even if that doesn't happen the cycle will continue when the old one passes away and will need to get another so that one isn't lonely.
On the other hand I'm worried that if I don't get another bird for it, it will become depressed and die because of it.
Also, any help on attracting the bird back? (they were kept outside) I mean, the male will call for it of course but I can't leave the cage open because that one will get out too. If the bird doesn't come back it will eventually die because it never learnt to do anything for itself. I thought about letting the other one go too and hopefully they'd find each other but then thought of what I just said above.
What do I do?
Thanks.