Green singers plucking themselves

[Summer Bird]

For some extra money, I am currently working part-time at a local pet store that sells birds. The store has a pair of green singer finches that have been there for several months now. These birds have always seemed healthy and reasonably happy, but over the past few days I've noticed that they've been plucking their feathers on their chest regions. They then will carry the plucked feathers around in their beaks for quite awhile before eventually dropping them. Today when I was there I was horrified to see that the male is looking quite bald around the chest and neck (his crop is visible now), and the female isn't too bad (yet) but while I was watching, she reached down and pulled out one of her own chest feathers and then carried it all around the cage for several minutes.

My question is, what is causing these birds to do this? The way they carry the feathers around reminds me of nesting behavior, but I'm not sure if that's what it is. (They do not share a cage with other birds, by the way.) Does anyone have any ideas?

[B CAMP]

I think they want to nest but not really sure.

[L in Ontario]

I agree with Bill - they are wanting (a lot) to breed.

[lovemyfinch]

I agree with all of the above. They are known to supposedly have agressive breeding habits, but I think that this is what they are talking about.

[ikhom]

Give them nesting material. It should keep them busy and may stop plucking.

[Summer Bird]

Give them nesting material. It should keep them busy and may stop plucking.

Will do! I'll give them some grass hay and a canary nest when I go in tomorrow. Thanks for the help everyone.

[Summer Bird]

Unfortunately my manager decided not to allow them to have a nest. I hope they calm down and don't mutilate themselves any further.