Where do you keep your chippies? If in an outdoor aviary, can you take your other chippie out, and leave the door open? He may very well come home on his own before nightfall since he's out there all alone. If he's kept indoors and has gotten outdoors, maybe leaving a familiar toy he'll go into if he's tame, or a safe trap if not, with his favorite snacks outside? I've never had a chippie escape into the wild, but that's what I've read as working.