Posted: 05/10/2014 at 11:23
Phillipa, all the Police will do is tell you to inform the RSPCA. The RSPCA does have the power to remove animals, the Police do not and will not unless supported by the RSPCA. Entry powers can be granted by Magistrates Courts to both the Police and RSPCA via a warrant. As these chickens are in an enclosure on open ground a warrant isn't needed and the RSPCA can remove them without the assistance of the Police.
Dove is incorrect (sorry Dove), the RSPCA is our first port of call for any animal cruelty or neglect case. The police role is to support the RSPCA and will not take any action without direction from them, this is national police policy and legally the approach the courts favour in any subsequent prosecution.
I would take photographs or video from a phone to support what you have seen, this will be dated and help the RSPCA if it decides to take any legal action.
In all probability, they will ask the owner to sign the animals over to them and issue a warning, prosecutions are usually only undertaken in the more serious cases, or persistent cases of neglect.