This is common practice with the RPRA and they are skating on very thin ice!
If you as effectivly a non member (i guess your not a member of the RPRA if you keep rollers) have been given a 3rd partys details the RPRA are breaking the data protection act!
They don't know you from Adam, you could be a stray catcher etc etc.
The RPRA should take your details, ask you to keep the bird confined and contact the member whose responsibility it is to collect the bird etc.
Phil