Neil,
You could also report to AFCD as well.
They think it is the best way to protect their crop by hanging dead birds around. However, it is illegal in HK as all birds are protected in HK.
When telling them it is illegal to hang birds, some react very negative, saying something like "birds are more important than human". Some say "pls tell me how to protect my crop", some say "pls compensate the loss".
It is better to put CD or any reflective materials to get rid of the birds. If the problem is too serious, the farmers should actually "cage" their crops with suitable nets (not fishing net or mist net). It is their responsibility to protect their own crops properly and legally.
Cheers,
Captain