Does this sulphur crested cockatoo have BFDV?

[vish]

Hi Guys, 
I live in on the lagoon at Avoca Beach NSW and have a lot native birds visiting our property. It's a wonderful sight but from time to time we come across a bird in need. Yesterday, a adolescent sulphur crested cockatoo appeared in a our back yard. I can't fly, only flutters to the groound. It's stayed in the same spot all afternoon and over night standing in heavy rain and wind. Due to the continuing poor weather, I moved it to a protected outdoor area attached to my house. After reseacrhing on the internet, I'm concerned the bird has Beak and feather disease virus (BFDV). We called wires who will try to send someone around to check but they can't say when and may take days. We called the vet who said all they can do is euthenase the bird.
An adult cockatoo has been having around today and appeared to feed the adolescent from it's mouth at one point. Hoping someone can review the attached image and let us know if it's classic signs of BFDV (can't fly, no tail feathers, only a couple of yellow crest feathers) or is this just an underdeveloped bird that may have left the nest too early?
Also, if we should offer food, what can you suggest?

Any advice is appreciated



Many thanks
Vish 

[vish]

Hi, thank you so much for the info. The parent has come a few times but we have only witnessed one feeding. It's very scared of us so hand feeding is not an option. Have put down a variety of fruits and pellets.  It's started nibbling at the fruit but I'm worried it's going to dehydrate as I can't see how it's taken in fluids over the past 2 days. Have placed some water around but it's very wary of anything we put in there. Will let you know how it all goes.
Cheers.
Vish