A recent post I read today stated that there green singer sang `differently` to those on you tube. I too had one like this that very unfortunately died prematurely.
If you listen to the following link on you tube at about 1.47 you will hear quite clear canary like warbles and trills from a Green Singer that i found whilst searching You Tube this morning.
http://www.youtube.com/watch?v=5HaUaKnI ... re=channel
As stated in another post I feel the majority of Green Singers underperform because of lack of tutoring. But it seems that they too have the brain plasticity of there better known cousin (domestic canary) and can be tutored to learn possibly just about any other finch song (there was also a canary / green singer hybrid trained for goldfinch posted recently). The bird in the link clearly has been influenced by a Canary (possibly like mine had) and the result is (to my ear) an enhanced song with more structure. The owner has another which sings a song like no other singer I have heard (at point 2.00).
http://www.youtube.com/watch?v=hli6vsE9 ... re=channel
I do prefer the bird in the first link as have always liked the canary type warble but it has always sounded a little harsh/ metallic and too loud . The Green Singer in my opinion (humble opinion) is a much sweeter pitched bird, certainly a better looking bird, so much more active and altogether more delicate in appearance with a lovelly Saffron colour (in well conditioned individuals).
With the right training these little wonders could replicate the canary song with a sweeter voice!
The trained birds would then pass the new song onto the next generation and a strain of superior Green Singers could be propogated.
In such a case I could think of no other small finch that would fit the bill for all round attractiveness and desirability!
