This happend to my friend, and I've read about it online, and i thought id post it here. When incubating eggs, its IMPERITIVE, that you keep the temp stable. if for just a short time, the temp rises oh, a few degrees, it could be catastophic! it can restult in curled toes, and maybe even a extra few legs! this almost always causes the bird pain, and makes it harder to get around. usally, the bird has to be put down.
well, i hope this helps prevent a few mishaps.
