I kept up with your post marisa0820. I really didn't think it likely for someone to actually steal animals. I thought they would go for other valuables such as jewelry, heck, even the tv, before the gliders.
If all they took was the gliders, then it is possible that you know these people, since they would have known you had them. My aunt had something similar happening to her. She had a Hyacinth macaw and one day she came home to find it gone (toys, food, and a small traveling cage she had). The strange thing is that that was all they had taken, and however much she had looked in her area, she couldn't find it (she had looked into pet stores and any posts of someone trying to sell a hyacinth macaw). Until one day some neighbors came to ask her for help with a bird their children had brought home (my aunt works with wild life and she is very knowledgeable about exotic animals), it just so happened it was her macaw (the toys were the same and they still kept it in the same travel cage they had stolen it in). All the parents had to say for themselves is that their children had told them that they had just found it and were taking care of it, and they believe them! Anyways, my aunt did not wait for the adolescents to be back to question them, she just took her bird and stormed out of the place (she even moved out soon after).
I don't know how they managed to steal it though, I thought the parrot would be quite vocal and aggressive about strangers handling it. Though gliders don't have many defense mechanisms, I would have thought they would be very loud at least; but then again, it happened during the day, and so they could have been cery sleepy.
I would say try all that marisa0820 suggested you to do, and check with your neighbors, at least to ask if they saw anything.
I hope you can find them.