Thanks to dlhunicorn, SeaChick and hinkjc for advice on my sick bird, "Slate". Sadly, she died yesterday , and I clearly have a lot to learn about diagnosing sick birds!!! What happened: By Monday morning, I was beginning to think that she must be eggbound, based on occassional appearance of straining. I finally (after MUCH searching) found a Vet who would look at her, and he confirmed that she was severly eggbound. He couldn't easily release the egg and had to anaesthesize her and cut her open some. He was unable to find any cervix, and found much internal damage and necrotic tissue inside, as well as a second egg in the queue. He thought she may have had some kind of birth defect that resulted in no cervix? Anyone ever seen that before??? Bottom line: we opted to "euthanize" her because there was no way she would be able to recover from her internal injuries. Needless to say, this has all been sad and distressing, but I do have to admit that I'm also a bit relieved that she didn't have an infectious disease that could have wiped out ALL my birds. I hope that if I ever have an eggbound chicken again I'll be able to recognize sooner. Thanks again to everyone for the help in troubleshooting.