How to tell a female and male society finch apart?

My finch is missing feathers over night? Help?!?

• I have two finches. One is a society finch and the other is a spice finch. I've had them since about two months now. For the past two months, they have really seemed to be very fond of each other (they cuddle and sleep together and do not fight with each other.) Lately I have noticed that my society finch's tail had been looking different, as if the feathers were just messed up. Shockingly, I came home from school today and a large spot on the back of my society finch's neck is bare! No feathers! I also noticed while it was flying from on spot to another that it appears to have no feathers throughout his back to his tail. I'm very worried about this. The spice finch appears to look normal and healthy, no feather plucking. I've been watching each of their behaviors today. Unusually, they have been obsessively rubbing their beaks on posts in their cage. I haven't seen any real signs that the spice finch is plucking the feathers out of the society finch, even though it was my first assumption. I do see that my society finch may be plucking out his own feathers, but it's hard to tell.... So really, why is my finch does this to himself? and how can I help him!? I don't want him to lose his feathers :( It looks so terrible.

• Answer:

  hello, i am soo sorry to hear about your bird, i too had a problem with a bird who looked healthy but was loosing his feathers! (i own a canary) .... do you know if they have mites? because that could be it! if that's the case your avian vet will give him some ivermectin shots (on the skin) and in no time you will have a feathery lil finch :)